It's connectivity, reliable power, reliable cooling, and security.

The actual space isn't a big deal, but the entire environment has large fixed costs.

In abstract yeah.

In practice, all that except connectivity is relatively easy to have on-site.

Connectivity is highly dependent on the business location, local providers, their business plans and their willingness to go out of their way to serve the clients.

And I am not talking only about bandwidth, but also reserve lines and latency.