[ghaff]

Another point that I’m not sure gets much attention is that, as these companies build huge campuses and spread out to multiple locations across a region, how co-located are employees anyway? Sure you can move people around to be with primary teams but it’s certainly not like everyone can pop over to talk with someone or can depend on a lot of serendipitous hallway conversations.

[SFLemonade]

That's a great point. Google tends to collocate teams by product, so that may be their answer to this. But it's true that you'll eventually reach a scale where you're going to have daily remote interactions, regardless of whether those people are in an office or not. Even at the Googleplex, if you're in an office across campus, it's better to connect to the meeting remotely than walk over.