First and foremost, backups. Back up everything and back up often. Immutability can’t do anything for critical hardware failure.
Issues happening on something only running container workloads isn’t common but I think it’s worth the extra little effort to reduce the risk even further. Fedora CoreOS or Flatcar is ideal since its declarative nature makes it easily reproducible. Fedora IOT can get you there too, but it doesn’t use ignition so you’ll be setting the server up manually.
Immutability is good. Declarative configuration is good. Manage cattle, not a pet.
Proxmox is sort of the gold standard for homelab server operating systems. Runs containers and VMs.
If you’re not into Proxmox, look into Fedora Server with Cockpit. Web UI for server management. Fedora CoreOS is an immutable variant of Server that would make more sense for a hypervisor, IMO.