That's a really nice setup! I run most of my things on a docker swarm (the docker hosts are VMs running on Proxmox hosts), though that was an overkill in retrospect, and causes more problems with no practical advantages.
The range of services I run is similar to yours, but I also have a bunch of services for personal finance (beancont/fava, as well as automatic importers and such), a more extensive media setup (with qBitTorrent and *arr apps), a gitea server, and a vaultwarden instance.
No, it absolutely uses a Linux kernel.