Shadowrun, GURPS, Rifts, the entire d20 line...
Not so much, no. What you're asking for is an absolute 1:1 correspondence. As long as you stick to a list, you might be OK, but the moment you set foot on ground not completely, precisely covered by the rules, you're in trouble. 5e starts out on that ground, because the alternative is just too limiting and rules-heavy.
The PC rules were so far off from the NPC rules in 4E that trying to reconcile them was impractical.
It would be impractical to try to reconcile rules for jet aircraft and pasta makers, too. There's nothing to reconcile, they're different, they have entirely different functions in the context of the game. 5e, fortunately also recognizes that difference.
Speaking in terms of default modes...
A DC 20 obstacle has an inherent meaning in the fiction of 5e, across levels and adventures, that stays the same - it is always a Hard obstacle, in terms of the world. That means that if you have a 95% chance to beat that DC, then you are a MASTER at that task because you have reduced Hard actions to mere trivialities.
Yet, he somehow says "wow, that was hard?" No, it was easy for him, routine.
In 4e, a DC 20 obstacle doesn't have an inherent meaning in the world, it is assigned meaning by the DM based on the circumstances it's encountered in. It might be hard for level 1 characters (DM: "Oh, it's an insidious dwarven design made from adamantium!"). It might be easy for a level 10 character (DM: "Oh, it's some rusty tin thing.")
'Easy' for a 10th level character, means easy /for a 10th level character/. Hard for a level 1 character means only that, in the context of the typical skill levels at 1st level. DC 20 is DC 20, regardless. It might represent any of a variety of equally-difficult locks, of course, but that's because d20 (3e, 4e, 5e, whatever) simply doesn't have the granularity to give every possible lock in the universe a unique DC.
It might also have the same meaning (In both cases, the DM describes it as adamantium and dwarven)
Very likely. Well, probably not adamantine, that material shows itself at higher levels. It might be the same lock. Two identical locks. Or two comparable locks of identical (to the level of granularity allowed in d20) difficulty.
Here's another example.
It is /easy/ to see that a DC 20 lock may be hard for a low-level character to open, easy for a high level one, and difficult for untrained persons in general to open. Yet, to the willfully ignorant, it may be /hard/ to admit that. The difficulty varies with the context of the person attempting the task.
Person with an ounce of common sense trying to understand this concept: easy.
Person with no sense of proportion desperately trying to find fault where none exists: hard.
The latter design is greatly flexible, because its fiction is largely irrelevant - what matters to the game is the maths. The former design is not quite as flexible, but it grants that achievement-juice much more directly and with less reliance on individual DMs to patch it up.
The is, in fact, no difference. Both systems are d20 vs a target number. Both depend on the DM to choose that target number.
And it can be turned into the latter system with very little effort.
And vice-versa, because they're both just d20.
IMXP, its systems as presented in the rulebooks rarely tolerate much of the unexpected. Indeed, I find more than a bit of a "tournament" mentality in a lot of 4e: make everything level and equal and remove many of the variables, keep everything smooth, all of those oddities are distractions.
You find what you go looking for. If you look long enough, hard enough, and ignore all contrary evidence.
A change in narrative fiction can feel hollow and meaningless absent a mechanical relevance. And the change in narrative fiction between a balor and an orc has little mechanical relevance (more complex, but the same balance).
Nonsense.
There are going to be roughly equivalent relative challenges in any system. A 1st level 5e fighter and a 10th level one will hit different ACs with the same natural roll. That doesn't make those different ACs 'the same.' That holds true whether you're on the Bounded Accuracy reservation, or running on the treadmill, or using THAC0 or BAB.
Balor and ordinary orc are not among them in any edition of D&D, regardless of the the relative power of the PCs, or the natural die roll they hit them on. Orcs just effing hit things. They're like 5e fighters, that way. Balors have a laundry list of special abilities - they have more laundry (90% of which don't matter when it's banished or annihilated in one round) in some eds than others, but there's always a lot more to it than an orc.
In 5e, you could take that balor on at level 10 and come away with your lives if you're clever about it. In 4e (and most earlier e's), you lack the prerequisites for that encounter, so it will simply crush you.
Yes. There is much more room for meaningful advancement in 4e. It's a downside of bounded accuracy. 30 levels vs 20 will do that, too. It's unfortunate that you can't have a Balor in 5e that lives up to it's fearsome rep, but can be ganked by a large enough number of lower-level attackers fairly efficiently. It's up to the DM to cover that particular system weakness.
Oh, or 5e gives so much more advancement because characters gain twice as many hps over 2/3rds as many levels and their damage balloons similarly.
Take your pick.
That's one of the significant changes bounded accuracy brings in - it's not just bigger numbers and different powers, it's a true change relative to the campaign world according to the RAW.
Again, you're spouting nonsense. For one thing, 5e 'RAW' is just a starting point, you're expected to deviate from it all the time, so 'true change according to the RAW' is pretty thoroughly meaningless. For another, pretending that gaining a +20 over 20 level is less of a change than gaining +4 over 20 levels, because the DM in the former case has better tools to design challenges, is just pretending.
Not everyone experiences this (especially more narrative-focused tables), but you'd be wrong to assert that this kind of criticism is "nonsense" just because you're personally ignorant of it.
It's nonsense because it makes no sense. It's not a matter of ignorance on anyone's part - the d20 rules are simply not that obscure.
You can pretend that a game where the fighter hits an orc on a natural 8 and, many levels latter a balor on a natural 8, is totally different from a game in which a fighter hits an orc an a natural 9, and, many levels later, hits a balor on a natural 9, and that one is therefor 'better' than the other, but that's all you're doing: pretending.
The reality is that 5e and 4e do basically the same thing: they advance all characters trained skills, and proficient attacks at the same steady rate, regardless of class. That's different from 3.x, and earlier eds, where your class made a big difference to the rate at which your attacks and skills (if you had any) advanced. 4e has more rapid numerical advancement over a wider level range, 5e's is much slower over somewhat fewer levels. That's little more than cosmetic, though it does have some consequences when it comes to designing encounters.
