What this means is that FAANG is actually paying what it needs to pay to get employees, otherwise many people would simply work elsewhere.
There is a myth that working at FAANG is amazing for everybody, but most people I know there are actually kind of miserable and doing fairly dull work for which they are massively overqualified. Nonetheless, these companies have money and they want the "best" (in their eyes) people for everything, so they pay for it... Well, it's a decent deal.