I swear every single JRPG has some kind of precursor race. It's to the point where I'd be interested in seeing alternative ways to keep things fascinating. I actually do love the mystery that "mysterious vanished" precursor races bring, but surely they're not the only way to give that feeling?
Tbf, that's a major plot point of the game (if not the entire plot itself), rather than a "sidenote" (like Final Fantasy games - love them but they do that a lot).
I put it off for years and finally picked it up this past December and man I wish I'd picked it up sooner. May be my favorite gaming experience of the last decade. And I loved the direction they took with Aloy as a character. Can't wait to try Forbidden West soon