Yeah, 3E had its own problems, that's for sure, but I think 5E and this "bounded accuracy" thing was really the best approach to skills and attacks. It allows any type of skill, attack or challenge to remain relevant, and still leaves enough room to be really good at something and make it count.
One thing I noticed that bothered me when I was making a "plan" for my Pathfinder 2E Kingmaker character: You can't increase skills "out of turn". You get your classes/levels skill increases, and that's almost all you can get. My Fighter was basically chosen to become the king-in-the-making for the group, and covering not just the Fighter skills and the social skills in the long run was almost impossible,and the way lots of stuff is set up as rolls against the difficulty of your level, I already forsee that it will be a struggle... I wouldn't mind spending feats on it, but it seems there isn't anything to boost skill proficiency level...
I can't reconcile the first paragraph with the second. The bounded accuracy problem is that it makes skills less meaningful because everyone can roll; it creates points where having a skill is less meaningful than having the attributes. Combined with the lack of distinction with skill along with the difficulty in getting new ones makes it rough for anyone who wants to engage with it past the most cursory level. Like you talk about how you can't increase skills "out of turn" in PF2, but that's way worse in 5E where you can only get new skills by spending a Feat, which are both rare and are competing with a bunch of different (and often build-crucial, especially for Martials) feats and ASIs. This was one of the biggest problems I had back when 5E started and it's one of the things I've seen people mess around with to create more meaningful distinctions between those who have skills and those who don't. If you don't like plans, then 5E's version of skills is terrible because if you don't plan for what you want at the beginning, you're probably not going to have it (or at least have it for quite a while).
I also don't really get having problems creating a fighter with social skills in PF2 given the spread of attribute boosts they hand out. You might not be able to specialize in every charisma skill, but you can probably get one or two. Like, you talk about "Fighter Skills", but I'm not sure what you really need outside of "Athletics" to do just about all the things you need to do as a Fighter. What are you juggling here?
But honestly, when it comes to level-based systems, I generally think PF2 does a pretty good job of it. There's a lot more room to play with and use GM's discretion without breaking the system; it's easier to hand out a skill in something because it doesn't instantly boost up to maximum like 5E, while it's also harder to max out and break the system through numbers given how the actual math works.