Also because "four years at FAANG -> CTO or Development Lead (with a major hiring component) of a smallish funded startup" is a really common path, and those folks often bring along those interviewing processes. Startup founders & salespeople love to be able to say "so-and-so came to us from Google" when talking to e.g. potential investors or major sales prospects, but often can't really afford great managers or well-seasoned developers from those places, most of the time, so you see a lot of this "this is my fourth job ever, counting an internship, and I've never held a position higher than Team Lead in which I still mostly wrote code, and I've been in industry less than ten years total, but half of that was at FAANG and one time I presented at a minor conference and that's on Youtube, so now I'm CTO of [25-employee startup]"

I think those places are screwing up, since they usually can't match FAANG comp and anyone who is great at those kinds of interviews will just go to FAANG instead, but whatever.