Why is it better for everyone? I imagine we have the current hubs because with a more liquid job market it makes finding jobs and employees easier. It's proba

Why is it better for everyone? I imagine we have the current hubs because with a more liquid job market it makes finding jobs and employees easier. It's probably also good for investment since having many potential acquirers nearby increases the chance of a positive exit. I guess it's kind of an insurance against terrible (local) government policies if people move from city to city when one of them screws up. That doesn't sound like a terribly efficient system though.