At every large company, especially after the growth period, there will be 10-15% of people which can absolutely be fired without any effect on operations.
It is difficult to let them go en masse because the people and the media will happily go with torches and forks to blame you with everything that’s wrong with capitalism. Unless everyone else in the market is also in the firing mood.
Big Tech views layoffs as an opportunity long overdue, and now it is the best time for them to execute without too much outcry.