I'm just going to point out that besides containers, systemd can now manage virtual machines:
systemd version we added systemd-vmspawn. It's a small wrapper around qemu, which has the point of making it as nice and simple to use qemu as it is to use nspawn.
The idea is that we provide a roughly command line equivalent interface to VMs as for containers, so that it really is as easy to invoke a VM as it already is to invoke a container, supporting both boot from DDIs and boot from directories.