Honestly I've been loving systemd-nspawn using mkosi to build containers, distroless ones too at that where sensible. Works a treat for building vms too.

Scales wonderfully, fine grained permissions and configuration are exactly how you'd hope coming from systemd services. I appreciate it leverages various linux-isms like btrfs snapshots for faster read only or ephemeral containers.

People still by large have this weird assumption that you can only do OS containers with nspawn, never too sure where that idea came from.