>why the fuck dont they put these data monstrocities in any number of thousands of empty giant office towers littering city centers everywhere

Big problem is providing enough electricity to an office tower.

A local company built a test T3 datacenter in an office building. Heaps of floorspace. But they cant get enough juice in, they started selling racks with less and less guaranteed supply. IIRC the site is basically forever capped at 2.5MW.

Whats worse is that the inner city location makes it an absolute favorite with telcos, but the telcos cant put their towering monstrous electricity sucking routers in for fear of browning the site (We tried, we were politely asked to leave).

I was walking past the construction of a new site just yesterday and they had the electrical switchboards on the pavement being prepped for being craned in through the open roof. Theres no way you would be able to easily retrofit for that sort of electrical supply.