The nice thing about Bay Area is that everyone is on the "same page" (call it an echo chamber maybe)
You can go into any meeting and mention some technical thing like LangChain and everyone knows what u are talking about. No need to waste 15 minutes getting ppl up 2 speed. Outside the Bay Area, Europe etc. you'd mostly get blank stares, even in an accelerator or hub
If the cost of office space were a concern, it'd be difficult to explain why they're anywhere near the Bay Area at all.