I see this sentiment (that if someone can get a FANG job then they can get a startup job easily) on here all the time, and it is a belief that needs to die.

When I took an offer at Google I had literally been searching for months and had no other offers.

Years later, after a couple years career break I had been searching for months and could hardly get startups to talk to me, but X and Meta seemed very interested (I was not interested in them).

I know it sounds intuitive that if someone can land a gig at one of the large companies then they can easily get a job at someplace that's doing "good work" but this is often not the case.