I think this is one of the reasons why Pathfinder 2e has been doing so well.

It's a middle ish ground and it feels good to progress.

My current issues with it are how underpowered the items are. So boring.

Differentiation comes from role play, which is the least interesting part of the game for me.

Can you explain why you would play a TTRPG if you're not interested in role play? Seems like a battle sim like warhammer, or just a video game might be the thing you're looking for.

As a DM, the cooperative story telling IS the interesting part. D&D has never been an airtight game system, it's a bunch if hand waving to give just enough illusion of structure and randomness so you don't feel like you're just arbitrarily deciding everything yourselves. But at the end of the day, you are. The characters and story you're left with is the only thing of value.

2024 is even worse. On top of that, they also stack extra abilities, and try to give everyone everything.

One of these days I should try Pathfinder

I haven't played any 3.5e proper, but I understand Pillars of Eternity 1 is largely based on it, and I've played a handful of the 2e games. I dig a lot of the changes in 5e. I wouldn't say the power is so flat that the differentiation only comes down to role play; I'd say a lot of it comes from the apples and oranges comparisons between classes, like things beyond to-hit roles. Your fighter has no AoE attacks like the wizard has but has Second Wind and Action Surge, for instance. The advantage to flattening the differences a bit more is that your character's role is less preordained ("you are playing class X, so you must be responsible for Y") and that you are less hamstrung by the absence of one particular role, which scales better to small parties.

I started TTRPGs with Pathfinder (1e). Some people talk about it like some impossible thing to play. It does have a lot more detail than 5e, but it isn't that bad. (I did play one character as a wrestler, who did grappling a lot, which is notoriously one of the most complex systems.)

5e sells itself as being simple, and it is in how little control it gives you. However, the rules are anything but simple. There's so many contradictions and stipulations every player has to memorize. It's a mess. For example, some spells can be used as bonus actions, but not if you've already cast a spell, except for some that can anyway. It's stupid.

Pathfinder 2e seems to make things so much simpler for everything, while still giving players freedom. Actions are just actions. If you've got the points you can use them for anything. Movement, attacks, spells, etc. Pretty much everything just is what it says.

3.5e being the best is an opinion I've heard for my entire life. I would say preferring 5e is a more unpopular opinion.

5e character progression does feel kind of bland.

I feel the 5e rules are poorly organized, too. Lots of interdependent rules scattered far from each other in the books, and sometimes buried in the middle of seemingly unrelated sections, so unless you've memorized multiple chapters, understanding how to resolve common situations sometimes requires stopping the game for 15-30 minutes while someone digs through the books to find all the relevant factors. Even when you do find the relevant info, it's often in ambiguous language describing what could have been made perfectly clear with a few keywords. The books are pretty, and the text might be nice to read for entertainment, but they're pretty bad the the job of being game manuals.

Does 3.5e use the d20 system? Does it have the advantage/disadvantage mechanic? I like those aspects of 5e; they're simple and they help keep games moving along.

Maybe I should give it a try. Or perhaps 4e, which I have read does a better job of clearly defining its gameplay mechanics.

I liked 4e the best.