Depends on your threat model. For someone who works in cybersecurity, the hard seperationo files per-project, easily split networking to different VPNs between VMs, and being able to keep sensitive data on a basically air-gapped VM that you can only copy to clipboard from is amazing. And with templates getting a stack of VMs for a new project running is pretty quick.

QubeOS is one of the coolest OSes around, if you work for multilple customers and/or take your data security seriously.

It's true that I have not considered it from the AI-slopworks PoV, but in general doing development in a container is probably a must nowadays anyway, so why not have a system build around it. It's not like virtualization is any difficult.