So it makes sense to me that Google, which derives most of its revenue from search, would find the advent of LLMs to be existential to its core business. 

But why do you think Meta is investing as much in AI, given that social networks are pretty sticky and wouldn't necessarily be impacted from a business model standpoint?

feels like ai would play a huge role in metaverse-ish stuff? eg generative reality, ai friends, things like that

This was my thinking as well, ai friendships along with ‘in memorium’ style - speak with the dead type stuff.