That’s what I wanted to say docker is only designed with specific goal to have one process running per container. So to run a system like Sovereign will need many many containers, one each for each daemon and then environment variables for each config settings. It’s a nightmare to manage. LXD is designed for multi-process with proper init and do not suffer zombie process problem of docker and unlike Docker supports unprivileged containers.

Personally I will prefer model like Guix System instead of container to run systems and services.I find that solution to be much more elegant than Linux containers or distributions. Linux containers initially came as chroot, jails and zones and than addition of cgroups and namespaces by google made it popular as lxc and later adopted and forked by Docker to make something complicated. These are bolt on solution to have immutable infrastructure. Guix is designed from ground up to be new OS for 21st century server and application infrastructure. May be it will or one of its derivative will become mainstream in time to come.