I think you may be underestimating the size of cities. Even San Francisco, famously small for a major city, is 15 times (at approx. 30k acres) the size of the physically largest data center in the US (Switch Reno Tahoe) at 2,000 acres. That's still just 1/7th the size of Manhattan.

I won't argue that 2,000 acres isn't huge for a data center, but just trying to put numbers to the argument.