Mostly just as a wrapper for Docker. The main issue I've run into is Docker's union file system functionality doesn't work when backed by ZFS, so disk usage can balloon out of control. I wouldn't use this in production but don't tell me how to live my life mom.

Beyond various Docker stacks I also have a Certbot container that uses Snap (sigh), and Hashicorp Vault container which runs as a vanilla SystemD service. I run Wireguard as part of my OPNSense VM. That's something I would run in a VM since it's exposed to the internet. I have an older MinIO and Concourse CI Docker Compose config that I'd love to run in LXC but I suspect that isn't realistic.

Note on Vault, I haven't been able to get mlock to work (used to prevent sensitive memory from being swapped). By all accounts it should just work in LXC, but since it isn't and there's no swap on the host I just turned it off. I may migrate Vault to a VM at some point.

I'm personally just interested in lightweight environments with good enough isolation and don't break all the time over nothing. Docker mostly accomplishes that for me. LXC + Docker also mostly accomplishes that.

(My heart yearns for FreeBSD Jails but with decent tooling)