IMHO these hirings and firings are not about the present but about the future. Sure, Meta did great but Nokia also did great for a while after iPhone was introduced.
What is the latest cool Meta product which promises a bright future for the company? Well, llama is cool but it's not product and today's greatest social media sensation is TikTok.
I'm sure meta does have some great tech, in fact some of the work they did on VR with all these tens of billions of dollars is groundbreaking but that also failed as a product.
Why would they keep the workforce configuration the same if their current state is probably not what they want to be tomorrow?