Some of these strike me as things where the software _could_ exist, but it's either not FOSS, or I haven't heard of it yet.

For instance, there are LVM2 snapshots. Maybe those do affect performance. If the cost difference is big enough though, couldn't you just account for that in the budget?

I agree that literal "bare metal" sucks, but self-hosted with cloud characteristics (containers, virtualization) is not totally obsolete.