Managing hundreds or thousands of containers across hundreds or thousands of k8s nodes has a lot of operational challenges.
Especially in-house on bare metal.
But that's not what anyone is arguing here, nor what (to me it seems at least) uncloud is about. It's about simpler HA multinode setup with a single/low double digit containers.
Talos has made this super easy in my experience.
I don't think that argument matches with they "just need to run a bunch of containers across a few machines"
Which is fine because it absolutly matches the result.
You would not be able to operate hundreds or thousand of any nodes without operation complexlity and k8s helps you here a lot.