Parhfinder 2 (which I have not actually played yet) did not do that. They opted for streamlining the existing system by combining several similar subsystems into one (i.e. everything is a feat now). But the math is still there.

I disagree. I've played 5E and GM PF2E (so I'm biased, but informed). In PF2E there's no stacking bonuses of the same type, and there's only 3 bonus types now.

Also, while there's a ton of feats, Paizo didn't just toss everything into feats.

PF2E is built off of a few frameworks for subsystems, one of which being character creation. There's also the monster creation framework which allows homebrewing creatures and encounters that follow challenge rating suggestions. There's even guidelines for building your own subsystems for thibgs like investigation, chases, research, etc. That are easy to learn get you fairly close to what Paizo would design themselves.

Meanwhile, the streamlining of 5E that you're hinting at is WotC stripping out almost all character options. I always got tired of D&D campaigns by level 5 because your biggest meaningful choices are at 1st and 3rd level unless you start making multiclass abominations. And there's also little support for GM's, requiring each one to come up with their own rules for things like how ships work or designing magic items.

I'd rather have a system like PF2E that provides options, because you can always choose to ignore them and build your own thing. If you're playing 5E, you don't have that choice