The eventual utility of the Internet did not stop a lot of people losing a lot of money in the dotcom crash.
Anyway, it's clear an AI data center has utility for crunching AI inference, and that there is and will continue to be demand for AI inference. The trillion dollar question is whether you can make money doing this, and so far the answer is no.
Its not about "is a computer thoeretically useful" its about if it's going to deliver value to cover the cost of installing it in the first place over it's expected lifetime.
You aren't substituting generic compute: you're substituting highly optimized GPU dense server space. The application is more limited then it looks.