The math of PF2 is much stricter and tighter than any other version of D&D (AD&D, d20, 5E) with the possible exception of 4E.
4E and PF2 does not play at all the same. Most importantly, PF2 combat feels much more like d20 or 5E combat than 4E combat.
Yet, I see clear similarities in design approach, especially in the areas I like the least about PF2:
* both games swim in an ocean of "feats" (or powers or whatever you want to call them). This locks down both games, since you are not encouraged to improvise or "say yes", you're encouraged to "take 16 levels of Barbarian" (or whatever prerequisite). It also represents a huge opportunity for the publisher to veritably SPAM the marketplace with gazillions of little tiny variations of essentially the same thing.
This does NOT mean I see any resemblance to the AEDU structure. Character abilities work much more like "normal" (where 4E is the odd duck out)
* PF2 offers much less character customization power than d20 or 5E. (Note I'm speaking about the actual power, or impact, of your build choices!) That might surprise those blinded by the sheer deluge of choices at every level. But I consider the wealth of choices here to be a smokescreen. That is, you're given a lot of choices, but each one ultimately doesn't change much. Worse, they don't matter much even taken as a whole. Essentially, you're given a very limited freedom to change the smallest things at the end, but nothing fundamental. Example: as a fighter you can pick a feat that lets you make a strike against both the monster in front of you and the monster behind you. But when you realize the other feats let you strike two characters standing beside each other, or give you a reduced power attack against a single monster, and so on, and so forth, you realize the devs all along wanted to give you an extra attack. But you don't just get the extra attack! You get it doled out as incrementally as anyone possibly could. The choice you get isn't to get the extra attack or to become awesome in some other respect - you only get to choose which specific configuration your extra attack can be used for. This is what I mean by "the smallest thing at the end", as opposed to "can I get better AC or higher Saves instead of Extra Attack" or something (that both d20 and 5E easily offers). Meanwhile, juicy stuff such as a second damage die comes "free" as soon as you loot a given monster (either for the Striking weapon or enough gold to buy one). The GMG allows you to make that bonus built in, but not as a choice where you could instead gain a significantly larger defense or many more hit points or whatever. And it's not that you could pick up a different magic item with your 100 gold that granted you those things. Nope - once you select your class at first level, your abilities are pretty much locked in, all the way up to level 20. You will get an extra attack exactly at this level. You will get Evasion or similar at that level. Your AC increases in exact lockstep, and so does each of your saves, with zero customization. You will get bonus damage dice at these levels (all you can do is change it up as minimally as possible, if you use the default system where damage dice - for some inexplicable reason, most likely because playtesters cried out like babies - are external to your character; perhaps getting it a level early or a level late). While I do appreciate balance, this is going way WAY too far for my liking.
* both games feature as restricted and narrowed-down magic items as the publisher possibly can. You don't get anything more than what the devs consider the minimum. Items are restricted in multiple ways - only specific character builds can use them, you need to remember specific restrictions unique to each item, and you can't simply use them at will, you must nearly always keep track of daily uses or similar. And then there's Talismans, who fill me with unholy rage.