"You can’t put all your eggs in a basket given the probability that something is fd."

But you'd be doing that no matter what unless you're running each daemon on a different physical machine. That basket's just called "Xen" now instead of "OpenBSD". Worse, if the hypervisor has a bug that can be triggered from unprivileged guest code (i.e. as a non-root user in the guest OS), then any layers added in the guest are moot.