Not much about casting classes has really changed from 3.5. In fact, in many cases, classes like the Sorcerer got upgrades, as they now get real class features.
You can point to less spell slots, but the fact is, low level spell slots stopped mattering in 3.5; their effect was too weak compared to enemies you'd face, and the fact that save DC's scaled based on the spell level meant that only incredibly vulnerable enemies would fail their saves. Even with "caster level" automatically upgrading spells, when you're facing a CR 8 Gray Render with 125 hit points, what damage spell is even going to make a dent in the thing? A 10d6 Fireball that's going to do 35 damage?
What's different are fundamental changes to the rules themselves to keep the ceiling lower; there's no crazy prestige classes, Feats are less plentiful and top tier Feats like Shock Trooper simply don't exist. I remember early 5e, with people freaking out about what basically amounts to a nerfed Power Attack (ermagerd, -5 for +10 damage! Pfft, try -10 for +20 and then add Leap Attack and Shock Trooper...).
Concentration actually causes more damage to the game's fundamental balance, though it's easy to see how many people fail to see it; 3.5 was intended to have casters buffing the hell out of Fighters, who were designed to be the best targets for buffs. Of course, casters instead realized they could be amazingly good by buffing themselves. Now nobody is getting buffs, because most casters have better things to do with their concentration. Even something like Bless, which grants amazing accuracy buffs in a system that otherwise has accuracy progress at a glacial pace, is rarely picked over other spells.
The stat cap of 20 hurts martials badly as well; gone are the days where a low level Barbarian can down a potion of Bull's Strength and suddenly have 26 Strength giving them a +12 damage bonus with their two handed swings.
The biggest gutting of characters was effectively removing magic items from the game's calculations, bringing us back to the AD&D era where one lucky drop could completely warp the game's balance- it should be noted that in AD&D, magic items were, by design, made to favor the Fighter, and to shore up weak points in the class. All of that is pretty much gone now, as many DM's, seeing that items are optional, and not really seeing how adding, say +2 magic armor isn't going to unbalance their game (as there's no guidelines as to how/when/why you should let a character have such a bonus) have become very conservative.
I mean look at defense. In the first Tier of play, characters can easily shoot up to AC's of 20 or beyond, but while enemies keep getting better to hit chances, AC basically levels off. Eventually you're up against CR 9's with +11 to hit, making even a 21 AC (plate, shield, fighting style) being less valuable than resistance (since there's that 5% chance to get walloped for 12d6+7).
AC less than that starts becoming a joke, and classes like the Barbarian, Ranger, Rogue, and Monk who dare to enter melee risk being knocked into next week with regularity.
Yeah someone will say "but Rage! But bonus action Dodge!", and I'll point out that neither of those things is going to be available in every turn of every battle. Not to mention the fact that many Barbarians basically cede their AC anyways by granting constant advantage to their enemies.
Meanwhile, casters can gain all kinds of ways to buff all sorts of defenses; AC, saves, resistances, and that gold standard, preventing an enemy from being able to attack at all!
But that's not the worst of it, the worst is if you don't constantly keep everyone low on resources, something the game really isn't designed to do (monsters are not designed with the idea that people are going to be at 25, 50, 75, or 100% of resources, and in fact, they are designed with the idea that everyone is at full hit points every encounter, something that is simply not in the stars for groups without casters unless you are taking way more short rests- which has it's own effect on resources for many classes).
The worst is when the caster has some extra spell slots to play with. He didn't need to use them today. Or maybe we're taking a day off because it turns out, only getting back half your Hit Dice per diem eventually catches up to the melee guys.
And the caster goes, well now, time to crank out a Simulacrum and start figuring out how to jump start an industrial revolution with Fabricate, or something equally ridiculous, while the best thing other classes can do is say "uh, can I pick somebody's pockets for spare change?" (and the Fighter can't even go looking for an arena fight, because he's trying to NOT take damage, lol).
Sure, a Fighter can outpace other classes in damage, if they're built to do so. And...that's about it. Utility in other aspects of the game is not a major concern for the class. They are made to fight, and that's mostly it. Which ignores the fact that D&D is supposed to have three tiers of play, not one.
So in a balanced game, 1/3 fighting, social interaction, exploration, the Fighter is good at one, and poor at the others. The Rogue is a little worse at fighting, but they can do consistent damage at range, and they get better social interaction and exploration. This seems balance.
Then you get the Paladin, who can be better than the Fighter in most every way. Wait, that doesn't seem right, does it?
And even if a Bladesinger was half the Fighter a Fighter is, that's on top of everything else they can do that the Fighter cannot.
People will say "lol, D&D isn't meant to be balanced" or "ha, try being a caster without a Fighter" but seriously, what are those attitudes doing in 2023? Everyone should have equal potential to share the spotlight, it's ludicrous that someone would be given a smaller piece of the pie and that's considered ok.
Plus, about that "needing Fighters"...do you, really? Clerics can have a stronger defense package than the Fighter, be better at locking down enemies, can grant themselves more hit points and have better ways to recover the same. Maybe a Wizard does less damage, but they have more ways to turn a fight into a non-encounter, something the Fighter simply cannot do.
I know that I'm not going to sway any opinions here; but if you're running a game and have never had to stop the action entirely because a caster has done something that seems completely out of bounds, yet turns out to be perfectly legal, I don't know what to say.
My experience has been that that sort of thing happens at least once a session, lol.
You can point to less spell slots, but the fact is, low level spell slots stopped mattering in 3.5; their effect was too weak compared to enemies you'd face, and the fact that save DC's scaled based on the spell level meant that only incredibly vulnerable enemies would fail their saves. Even with "caster level" automatically upgrading spells, when you're facing a CR 8 Gray Render with 125 hit points, what damage spell is even going to make a dent in the thing? A 10d6 Fireball that's going to do 35 damage?
What's different are fundamental changes to the rules themselves to keep the ceiling lower; there's no crazy prestige classes, Feats are less plentiful and top tier Feats like Shock Trooper simply don't exist. I remember early 5e, with people freaking out about what basically amounts to a nerfed Power Attack (ermagerd, -5 for +10 damage! Pfft, try -10 for +20 and then add Leap Attack and Shock Trooper...).
Concentration actually causes more damage to the game's fundamental balance, though it's easy to see how many people fail to see it; 3.5 was intended to have casters buffing the hell out of Fighters, who were designed to be the best targets for buffs. Of course, casters instead realized they could be amazingly good by buffing themselves. Now nobody is getting buffs, because most casters have better things to do with their concentration. Even something like Bless, which grants amazing accuracy buffs in a system that otherwise has accuracy progress at a glacial pace, is rarely picked over other spells.
The stat cap of 20 hurts martials badly as well; gone are the days where a low level Barbarian can down a potion of Bull's Strength and suddenly have 26 Strength giving them a +12 damage bonus with their two handed swings.
The biggest gutting of characters was effectively removing magic items from the game's calculations, bringing us back to the AD&D era where one lucky drop could completely warp the game's balance- it should be noted that in AD&D, magic items were, by design, made to favor the Fighter, and to shore up weak points in the class. All of that is pretty much gone now, as many DM's, seeing that items are optional, and not really seeing how adding, say +2 magic armor isn't going to unbalance their game (as there's no guidelines as to how/when/why you should let a character have such a bonus) have become very conservative.
I mean look at defense. In the first Tier of play, characters can easily shoot up to AC's of 20 or beyond, but while enemies keep getting better to hit chances, AC basically levels off. Eventually you're up against CR 9's with +11 to hit, making even a 21 AC (plate, shield, fighting style) being less valuable than resistance (since there's that 5% chance to get walloped for 12d6+7).
AC less than that starts becoming a joke, and classes like the Barbarian, Ranger, Rogue, and Monk who dare to enter melee risk being knocked into next week with regularity.
Yeah someone will say "but Rage! But bonus action Dodge!", and I'll point out that neither of those things is going to be available in every turn of every battle. Not to mention the fact that many Barbarians basically cede their AC anyways by granting constant advantage to their enemies.
Meanwhile, casters can gain all kinds of ways to buff all sorts of defenses; AC, saves, resistances, and that gold standard, preventing an enemy from being able to attack at all!
But that's not the worst of it, the worst is if you don't constantly keep everyone low on resources, something the game really isn't designed to do (monsters are not designed with the idea that people are going to be at 25, 50, 75, or 100% of resources, and in fact, they are designed with the idea that everyone is at full hit points every encounter, something that is simply not in the stars for groups without casters unless you are taking way more short rests- which has it's own effect on resources for many classes).
The worst is when the caster has some extra spell slots to play with. He didn't need to use them today. Or maybe we're taking a day off because it turns out, only getting back half your Hit Dice per diem eventually catches up to the melee guys.
And the caster goes, well now, time to crank out a Simulacrum and start figuring out how to jump start an industrial revolution with Fabricate, or something equally ridiculous, while the best thing other classes can do is say "uh, can I pick somebody's pockets for spare change?" (and the Fighter can't even go looking for an arena fight, because he's trying to NOT take damage, lol).
Sure, a Fighter can outpace other classes in damage, if they're built to do so. And...that's about it. Utility in other aspects of the game is not a major concern for the class. They are made to fight, and that's mostly it. Which ignores the fact that D&D is supposed to have three tiers of play, not one.
So in a balanced game, 1/3 fighting, social interaction, exploration, the Fighter is good at one, and poor at the others. The Rogue is a little worse at fighting, but they can do consistent damage at range, and they get better social interaction and exploration. This seems balance.
Then you get the Paladin, who can be better than the Fighter in most every way. Wait, that doesn't seem right, does it?
And even if a Bladesinger was half the Fighter a Fighter is, that's on top of everything else they can do that the Fighter cannot.
People will say "lol, D&D isn't meant to be balanced" or "ha, try being a caster without a Fighter" but seriously, what are those attitudes doing in 2023? Everyone should have equal potential to share the spotlight, it's ludicrous that someone would be given a smaller piece of the pie and that's considered ok.
Plus, about that "needing Fighters"...do you, really? Clerics can have a stronger defense package than the Fighter, be better at locking down enemies, can grant themselves more hit points and have better ways to recover the same. Maybe a Wizard does less damage, but they have more ways to turn a fight into a non-encounter, something the Fighter simply cannot do.
I know that I'm not going to sway any opinions here; but if you're running a game and have never had to stop the action entirely because a caster has done something that seems completely out of bounds, yet turns out to be perfectly legal, I don't know what to say.
My experience has been that that sort of thing happens at least once a session, lol.