Yeah, but I think startups are a different bet - either on comp (betting on equity) or on learning (more access to building a company).
OP seemed to suggest that startups have trouble hiring because they don't pay enough and I think that's not entirely true from what I've seen. They don't pay more than FAANG which is expected, but they're not underpaying for that trade-off.
I do agree though that FAANG salaries have gotten extreme so it's a harder opportunity cost than it used to be. If you can swing $350k at Netflix or $200-400k+ total comp at the others and you work there for 5-10 years that's basically a small startup exit. I think it used to be less dramatic.
I think the misery of the technical interview process is actually the thing that limits mobility most. Some of my extremely capable friends (that do work at FAANGs) don't optimize on moving around or income as much as they could because the process is so painful and anxiety inducing.