It is... but the top tier companies pay dramatically more than the next tier down. Like, we're talking 30-50% difference once you count total comp.
(it's interesting, base salary is somewhat comparable... but stock and bonus are a big part of comp if you work at a FAANG company, and those... largely don't exist at third-tier companies.)
The top-tier employers also do a lot to bring up salary pressure on the lower tiers; if the FAANG companies didn't pay so much, the most desirable people wouldn't leave the lower paying companies, wouldn't make room for someone less desirable, etc... That's how I got my start; I didn't go to college, but I did work my way up through those smaller companies, into larger companies that paid better and better.
Though, salary for software engineers has been ticking up lately. I suppose I can thank the demand for engineers created by these tech companies for that.
Yup, that's what I'm saying. I'm just a sysadmin; I'd never gotten a bonus in my 20 years working as a programmer or sysadmin, mostly at tier 3 tech companies... not until I started working at a FAANG company these last few years, but the bonus + equity is a really significant portion of my compensation now, and brings the whole package from "nicely comfortable for someone who didn't go to college" to "wow"
In any case, moving to SV would only be worth it if salary+bonus were close to half a Megabuck, and I doubt there are more than a dozen engineers in the world making that kind of money as a FTE.