(FAANG salaries are not an "order of magnitude" higher than salaries at other U.S.-based companies for similar jobs.)
FAANG salaries are just at the level at which those companies discovered people are willing to sell their souls, or that is high enough to attract naive people who won't question why it pays more.
Maybe I'm just really bad at marketing/promoting myself or I gasp have to take work "below my pay grade" because it's still work and I've got bills, but I'm not netting six figures doing highly technical work (embedded development, electromechanical development, board layout and design, etc.). In the last five years I've had one in which I grossed six figures. I'd figure I just suck and am an outlier but I keep hearing the same stories from friends who are also not at big shops.