> I see a lot of people working at startups who got tired of doing things at big companies that just weren't that interesting to them. Those folks have often made enough money that they can afford to work at a startup for a few years because the work itself is more fun, the company has a mission they like, or they appreciate having a bigger day-to-day impact.

Those folks went through FAANG first (not startup first) though :). I don't know if they decided to move to startups for the experience/thrill/fun or they're just there so they can go back to FAANG and get the full 4-years RSU + sign-on.