Chapotraphouse

Well if you ask certain FT journalists and AI hypers saying that even if it is a bubble it will be fine, they will continue to be data centers and we will have even more and cheaper web services and data storage. But that ignores that there isn't enough demand for other uses, which is why they weren't being built at this level before. And those servers wouldn't need as much GPU power. In all likelyhood the ones that don't just get abandoned will be used for warehouses or niche factory production that needs the air handling, temperature control and large water inputs.

If you mean best uses if we stopped living under capitalism, then probably archives (both digital and physical, got that climate control and air filtration) and warehousing, and some niche manufacturing uses. Maybe indoor sports if you can rip out all the server racks and internals easily and have a large indoor space. They are near some populations, but usually are going to be at the outskirts of any town or city, if not rural areas, for the available cheap-er land, while being able to hook up to internet, power and water, and have less resistance to building from communities around. So community centers and internet nodes are probably less useful. Maybe emergency shelter, but it is mostly above ground construction so most natural disasters would be a crap shoot at best that it would be habitable but the surrounding area not. Maybe some form of quick temporary housing, but just like the major challenges of repurposing office buildings for housing, anything long term there is so much you have to change in a building not designed for housing to make it good housing that you are only coming out mildly ahead of tearing it down and starting over, best case scenario.

I really think this will be a bunch of abandoned architecture once the bubble pops.