FAANG companies have been laying people off at the moment, so it doesn't seem they are exactly suffering from a lack of workers. Until a year or so ago some of these companies were hiring people without any real work for them, just to deprive their competitors of talent.
> FAANG will argue that they are laying off people with skills they don't need, and there's a lack of people with skills they do need.
They are laying off workers (permanent residents and H1Bs alike) mostly to cut costs while all their competitors are doing it, thereby saving face.
Additionally they are signalling to investors that they are focused on cash generation and only investing in areas they think will serve that end in the near term.
Finally, they are preparing for a future where they need fewer workers per unit of revenue and profit growth, but in the short term, that just means a higher workload for those workers that remain.
