Have you looked at their numbers on and before 2022? They very much over-hired a crazy amount. Zuckerberg admitted as such through his statements on "over investing".

https://about.fb.com/news/2022/11/mark-zuckerberg-layoff-mes...

And if that wasn't enough: https://www.itpro.com/business/business-strategy/mark-zucker...

A lot of companies doubled in size due to the Covid surge, for questionable strategic reasons