You tax the revenue that the entity that owns the datacentre generates, like any other business.
Am I missing something?
The entities that own the data centers (the mag7) famously do not pay much in taxes due to their extensive use of tax havens and loopholes
First off business are taxed on profits not revenues, so a money losing business doesn't pay taxes.
Second if there is something that causes undesirable side effects (like a data center) you want to tax that activity specifically so the Corp with 8 data centers pays more then the Corp with 1.