De gustibus non disputandum est, of course, but there are other factors too. Consider Harry Potter's magic system. Does its seem non-magical to you? Perhaps you do, though I fear you'd lose me there. But if you don't, why? It's even more repeatable and powerful than 5e cantrips. Or take Gandalf, who lights his pipe with magic all the time, and could do way more if he didn't obey the Valar (and Eru Ilúvatar by proxy.) Given LOTR is a sort of gold standard for "magical" magic, what is the salient difference?
Certainly the Potterverse is
different from our own. Within the context of the fictional world, flying on a broom, say, or levitating objects with a spell is fairly mundane. From the standpoint of our world looking in, it's difficult for me (personally) to empathize or imagine myself within the Potterverse because of 1) how different it is (for example world or time breaking magic being apparently fairly common), and 2) how...caricaturish the whole thing comes across. Waving sticks and uttering silly, pseudolatin phrases to change reality.
As far as LOTR: Lighting a pipe with a magical spark doesn't come across as a gross, wonder-diluting display of magic to me personally. Magic overall in LOTR is quite subtle...which helps maintain the mystique of it IMO. And more often than not is invested in the craft of objects. Keep in mind that even Morgoth, the most powerful, magical being short of the creator deity (Eru Illuvatar) resorts to weapon use on the one occasion he is depicted in battle; rather than flying, hurling lightning bolts, or the like. Although clearly there was SOME magic also being used there "
Then Morgoth hurled aloft Grond, the Hammer of the Underworld, and swung it down like a bolt of thunder. But Fingolfin sprang aside, and Grond rent a mighty pit in the earth, whence smoke and fire darted." (Silmarillion, Ch.18 - Of the Ruin of Beleriand and the Fall of Fingolfin).
But this is different. Magic, by definition, breaks thermodynamics and conservation.
Our universe's laws just...
aren't laws in a universe with D&D magic. The best you get is something like Newton's laws:
excellent approximations in "narrow" cases (that is, when not in Einstein town or Heisen-burg, gosh I'm so punny!

)
Breaking physical laws just a little bit vs. frequently is a distinction without a difference. Either way, they aren't physical laws anymore, because that's literally what "physical laws"
means, that they aren't broken anywhere.
Magic effects are frequently written/designed without regard to real-world physics certainly...but at least with respect to conservation/thermodynamics...not necessarily? They just needs extra (or different) laws, forces, sources of energy to make them work. Regardless - generally speaking for myself at least, the farther a fictional world seems divorced from our reality the more difficult it is to empathize with or visualize myself in it. We still generally presume in the D&D that the default physical world has gravity, planetary curvature, conservation of momentum for most things, inertia, etc.
This I'll grant! But there are wrinkles. Over 100 creatures have (conditional) immunity to nonmagical weapons, and over 280 have conditional resistance. Over 90 have regeneration. Yet if we look at those which have both regeneration and one of those other two...we come up really short, with only five. Two of them are deity-level beings (Juiblex and Tiamat, the latter having no turn-off clause), two (constructs: bone worm and stone juggernaut) don't have a turn-off clause for their regeneration, and only the last ("spirit troll") has such a clause. So...on the one hand, creatures who have all three are essentially non-existent, but creatures who have only one are almost plentiful.
I was talking about the binary (boolean) presence of the traits. Not entirely sure why having multiple would be relevant here?
This develops into something that is extremely punishing for any party that doesn't have a spellcaster, again creating a situation where it is the spellcaster's best interests that the whole party must align itself around and which the DM must align their whole combat design around.
Presuming that a spellcaster is the only or even most effective way to bypass them. Magic weapons are usually amongst the more common magic items, at least in published adventures, not to mention torches, acid, oil, etc. Comparatively few monsters have outright weapon immunity. There are similarly plenty of monsters that give casters difficulty...or where the META favor direct physical attacks (or at least fall more quickly to weapon-focused classes) in my experience. Exceptions, variations, and DM-dependency of course.
If magic is going to cause this many problems, doesn't that mean we should (a) re-evaluate how magic is done, so it doesn't cause problems like this, and (b) look for ways to let off the pressure, so that players will be encouraged to do the things we want them to do, to have the thrilling, terrifying experiences you're (implicitly) advocating for?
One should
generally evaluate and, if necessary, re-evaluate rule mechanics that are causing problems in your particular game. Regardless of source. I don't, to the best of my recollection, typically have more issues with casters over non-casters in games I've run (as DM).
Personally, I think this is an artifact of...let's call it insufficient zeal on the part of DMs and players in describing things, rather than any consequence of the item being magical. Because I can make a totally "mundane" sword incredibly special, and I can make an absolutely unique one-of-a-kind powerful sword really boring if I so wish. That's a power that has never been taken from DMs. Consider:
Good descriptions certainly go a long way toward creating mystique or specialness as well.
It's a metaphor for how knock-down, drag-out this sort of conversation becomes.
Fair enough. If the goal is to force people to admit that one's personal views are the one, true way, sure. I personally discuss and debate a lot of different subjects, hobbies, and interests in a variety of forums over the internet. I see quite a lot of pathologies - needing to get the last word in, bruised egos, general unwillingness to admit being wrong, insistence that people's subjective opinions and experiences can be wrong in the first place. Rather frequently I observe people who essentially hold the same viewpoint engage in bitter, multi-page debates.
Sure, but again, the problem is and has always been that the Wizard's player has some control over whether this happens--and to what degree when it does. Hence, they have every reason, even if they want what is best for the party, to behave selfishly: to set up situations so that they will always have the most spells possible, and to minimize, mitigate, or montage their way out of situations where they don't have any (relevant) spells available. That is the fundamental incentive of the existing Vancian spellcasting rules, and it is an incentive which points away from the intended experience of play, whether one desires Old School "High Gygaxian" murderhole dungeon-heistery or New School "High-Flying Action" fantastical set-pieces, or basically anything else that isn't specifically Casters & Caddies.
Yes. But the non-casters trying to prevent the Wizard (or M-U) from getting their Doom Spell off would
also have
some control over whether and to what degree this happens. For example - using quick weapons or hordes of minions to make it more likely to get strikes in first (e.g. more likely to get a favorable initiative roll). Or stealthy combatants to assassinate the squishies beforehand. That's how tactics works?
We can do better--and we can ask WotC to do better. We can ask for a game that doesn't reward players for blowing their entire spell slot load in 1-3 encounters and then expecting a rest. That is an achievable goal. We just need to have the will, and the patience, to pursue it.
Ok, yeah. Though I find novaing to be as much a balance issue for non-casters as casters. Well...maybe SLIGHTLY less of the time since the VERY few subclasses that do not have ANY limited-use abilities (Thief Rogue, etc) are all non-casters.
In an absolutely abstract sense, I agree, but D&D magic isn't abstract. Fly is generally useful for anyone. Chromatic orb is a guaranteed spell pick for anyone who can get it, because it's extremely versatile. Invisibility is both powerful and widely-applicable (there's a reason Plato used the Allegory of the Ring.) And with the way 5e does Rituals, you don't even need to sacrifice spell slots to have a number of useful, powerful spells on tap whenever you need them, so long as you have 10 minutes to spare.
If you're talking about 1e/2e spell balance here, I'm going to have to bow out. It's been too many years (decades) since I've played to still have a sense of the meta. If you're talking 5e...Chromatic Orb, for example, deals fairly significantly less damage on average than, say, Magic Missile. And neither maintain fantastic usefulness at higher levels. I seem to recall it was widely acknowledged to be an outlier in 1e/2e? Invisibility and Fly are and were great and broadly useful spells, but hardly the solution to every problem; or even major subsets of problem. Certainly with multiple different effects available, in multiple different publications, you're eventually going to have some that are better balanced than others. Kind of the nature of the beast. And once again - not specific to casters.
I don't think I've ever experienced significant balance issues with ritual spells in 5e, outside of Leomund's Tiny Hut; for reasons previously outlined. Maybe some minor annoyances with dead, secret, and/or super-obscure writing and Comprehend Languages.
Even within a game world, DM-chosen rewards have plenty of ability to warp the degree of fun or power experienced by individual players. That's kinda why it's important to continually re-evaluate game balance as DM.
Okay, but how do you then deal with the players' perfectly legitimate response of "why did this work before, in essentially identical circumstances, but it doesn't work now? How is that fair?" This is another reason why I have such a poor opinion of any rules system which, in whole or in part, advocates for "viking hat" DM theory. In putting emphasis on just how absolutely powerful and unlimited the DM is, the game discourages seeking understanding and consensus, and instead pushes dominance and autocracy. But because players pretty obviously don't like being pushed around or denied a choice, the rules(/advice/etc.) must then emphasize sleight of hand and pretense, an attitude of "I know better than you what you actually want," further separating DM from player and cementing counter-productive power relationships.
Personally? I try to keep my rulings consistent. If that still results in balance or narrative issues, I look for in-game ways to get around them (e.g. "Can I get around this invisibility abuse by putting in guard dogs?"). If that STILL fails, I talk to my players about how and why the present ruling is no longer working for me. What I don't do is change things around behind the players' backs just because it's convenient. Of course, I'm human. And sometimes I forget things.
Okay. What about all the non-spell ways to pursue that? How do you keep up a constant, sustained time pressure to prevent such things while still making it remotely plausible? Doing so for a handful of sessions, maybe even an entire adventure, that's plausible. Being under such sustained assault that 3-4 hours of regular resting is totally fine, but 8 hours of resting would be completely unacceptable unless it just cannot be avoided....that's a much bigger ask.
I don't recall actually ever having any issues with non-spell or non-item ways of creating 5mwds? I've got a whole bag of tricks developed in response over the years. Examples would include: Reinforcements in an enemy stronghold, assassins/hunting parties that track down invaders, wandering monsters, defenses being organized, and YES plot-based timers. Recently in my games, I've been using/toying with the idea that long rests can ONLY occur in comfortable surroundings, such as inns or established camps in secured locations. (Established camps typically taking like half a day to set up - and still being subject to random encounters or inclement weather). So basically...it's not practical to long rest between travel encounters; and often impossible within hostile complexes/strongholds/dungeons (as if that was desirable before). Exiting often results in reinforcements, undead re-animating, other stuff moving in, etc. So there's an incentive to keep going even without some sort of external timer. Sleeping for the night in a not-so-comfortable location still prevents a character from gaining exhaustion as a result of sleep deprivation and at least still allows a Short Rest.
And of course if the PCs come up with an ingenious method of securing a location for a 5mwd, sometimes it's better to let them have it.
That is something multiple users on this very forum have explicitly (in the case of adding HP) said they like that 5e supports them doing.
I can't speak for other people. But it's not something I personally consider to be fair or fun. On either side of the DM screen.
"Rug pull" is either the part above, where you allow a plan to work on Session 12 but then forbid it on Session 14 for reasons the players either couldn't know in advance, or which they should have known in advance but because you didn't decide on them until Session 14 started, they "knew" something that (in a Doylist sense) "became" untrue. This is something the 5e DMG supports doing.
See above. Although - sometimes intelligent foes learn from their or their minions' failures. And sometimes powerful supernatural entities like gods or spirits with a vested interest in the PCs actions will intervene one way or another. And sometimes I tailor details of upcoming challenges to the players strengths or weaknesses to improve what I perceive to be fun for myself and my players. If I'm going to change things around, however, I'm going to drop clues that circumstances have changed. Which I guess makes it NOT a rug pull.
Returning to previous discussion though: Why isn't this applicable to casters in your estimation?
Illusionism is the DM technique that involves giving the appearance of real choices and consequences for player choices, while actually obviating those choices and giving fixed consequences. The classic example is the "quantum ogre," where the players may choose to go south to the Blue Forest or north to the Black Mountains. They make their choice, and along the way, they are attacked by an ogre. The players will then, quite rationally, think, "Because we went south to the Blue Forest, we encountered an ogre; if we had gone north, we would have avoided it." But this is not true with a DM who practices illusionism, because the DM will put that ogre on whichever path the players choose. This gives the appearance of having choices with consequences, but actually results in a perfectly linear adventure with the only difference being set-dressing. Unlike the previous, where it is more passive support (in the "you literally have to ask your DM if your class features work today, because they might decide they don't" sense), illusionism is much more directly mentioned, e.g. that bit of advice about skipping having a DC entirely and just letting the roll alone determine success (IIRC, it was something like 8 or less fails, 16 or more succeeds, everything in the middle, do whatever you think is best, "your players will never know.")
I do this too sometimes, I admit. It's not entirely practical to have TOO open a sandbox. Even so it's also important to have actual player agency. My typical homebrew adventure design is to brainstorm a set of possible encounters that could potentially occur in a variety of circumstances, tailoring specifics to what the PCs decide to do; and outline a number of different strategy pathways that could progress the plot forward. And, yeah, sometimes you have to scrap it all or ad lib. And sometimes you should have seen this coming.