Not many people want to work in those places though. And I say this as an engineer at Google living and working in Manhattan. NYC has a huge draw to it that most other places don't. Good luck attracting top talent to Des Moines or Orlando. Way more would rather work in NYC. You don't want to be in a one-company town either; if you left Google in Orlando, where else could you work without moving? There's no credible competition at the same tier.

Network effects are real.