I am skeptical we won't find a use for datacenters. The cooling, electricity, and servers can be reused for more mundane tasks. Sure, nVidia AI chips are wasted money if you can't find a use for them, but every other facet of infrastructure can be reused for any general-purpose computing. I would wager that even the GPUs can be repurposed to be powerful business servers if someone wrote some drivers to move more Java/JavaScript/Python routine processing to GPUs...it obviously won't be as efficient as a conventional CPU, but I am sure it can offset the price of buying new chips.
Just like we got a lot of cheap office furniture on eBay when the dot com bubble popped, I am sure there are going to be some firesales on cloud computing hardware or services when this horrid AI bubble finally pops.