> why does that need to be an OS?

It doesn't. You can still run Incus on other platforms of choice.

Sample size 1 here, but a big advantage of the 'full-stack' approach is things like network config, storage management, boot safety etc all work out of the box and you then get a single API (and nice client) for the whole machine. I get the benefits of cloud infra, like not having to care (too much) about sysadmin, from some hardware sitting in the corner.

I can literally

    incus launch images:nixos/unstable foo -t aws:m1.large

and start hacking.

Previously I would still need to be maintaining that base layer too. That still makes sense for some environments, but particularly for home I just want my lights and music to work, and be able to play.