A former tech CEO, who asked to remain anonymous to speak candidly, said Tuesday that companies such as Meta, Google, Amazon, and Twitter had hired “stupid amounts of people” in the last few years to work on “science projects.” Speaking specifically of Meta, the executive said, “You just wonder what are these 100,000-some people doing? The app doesn’t change much.”
“It’s surprisingly not hard for these big tech companies to cut large numbers of people without impacting the underlying revenue engine.”
and this last quote tells the whole story... these people were hired for somebody's pipe dream which did not materialize.
https://www.cnn.com/2023/03/14/media/meta-layoffs-reliable-sources/index.html