The thing with the cafeteria is that it reflects company culture. If you in the office sit at a desk in the Google search engine area or youtube or Waymo is hardly noticable. People have settled in an if the neighboring teams go home at "normal" times, the "startup" team will go home at those times. Also you have a hard time to keep the small team culture when directly embedded. And then corporates encourage changing jobs internal over leaving and hiring somebody else, which means that there are ties on all levels. Pulling out and having your own startup culture is hard. The cafeteria symbolizes that, as it is a social place and culture to large parts is a social thing.