We were doing this decades ago with engineer's HP C3600s under their desks. It wasn't AI, just low-priority HPC / fluid stuff batched out to hundreds of workstations.

And on IRIX, SunOS, and DG-UX boxes too. Once Linux existed for a bit, they were added to the fold. The software to do this - Condor - is still maintained.

https://pages.cs.wisc.edu/~danb/ref-v7.7.5/ref.html

That was the original pitch for Ian Murdock's Progeny startup in the late 90s: a Linux-based distributed filesystem for corporate desktops to boot into overnight for distributed computing.