Most FAANG have a high cost of living band and a regular band. The high cost of living band pays 15-30% extra for living in the Bay Area/NYC. Everywhere else pays the same whether it's Boston, Detroit, or the middle of the desert.
The Bay Area can mean Pacific Heights, or Concord. Probably half or 2/3 the cost of living in the latter.
Yeah - just that FAANG don't hire people outside top cities. So your middle of desert point is misleading.
most faang don't hire remote - but they do allow people to work remote in certain circumstances, they also tend to maintain smaller engineering offices all over the country so transferring isn't as difficult once your in.