At Google, HR has dictated to our team "no Bay-area hiring" for over a year now. It seems at least one company agrees with "There’s no surplus value in hiring in the Bay Area".
Since the wages paid are based on _local_ prevailing wage, and the Bay Area has the highest prevailing wage, Google will get cheaper engineers.
This also avoids the US immigration system, which is a terrible, expensive, stress inducing (performance sapping) thing for staff (and businesses) to interact with.
Finally, by distributing engineers to other countries, they counter some of the political "They're not _local_" arguments being made in various countries.
But FAANG are no longer hiring the smartest, most innovative people in the world. Those people served their purpose, and were instrumental in making FAANG huge. FAANG stays huge by keeping the lights on at minimal cost. That takes legions of schlubs to maintain and incrementally improve their massive infrastructure... and those are more plentifully, and cheaply, found elsewhere.