The gap between FAANG and non-FAANG salaries is quite substantial. For example, a Staff Engineer at an avg startup might get $250k base salary, in a HCOL area and maybe a 10-20% bonus.
But a FAANG Staff Engineer will get a similar base, and then $1mil in stock for 4 years.
-- Are there people outside of FAANG and Big Banks / HFT firms making those kinds of monies?
-- if So who are they? and what do they do?
These salaries listed are great salaries, no doubt, but they are not dramatically more than say, a guy running a successful local plumbing business. And the ceiling is limited as an employee, whereas it's virtually unlimited as a business owner.
If you aren't a shoo-in at FAANG and you want to make that kind of money, your best bet is to learn how to start and run a business. I don't mean try to launch a billion dollar social app that needs venture funding. I mean a SAAS that solves a boring problem for other businesses with money to spend.