It has been a few years, but for example breaking the display, bluetooth, power states/sleep, or wifi. Or subtly messing up dependencies of various other packages that I was trying. I just don't want the overhead of system administration. These days I mostly use VMs or WSL. But I am thinking that I want my host OS to be Linux.

Immutable saves you from packaging issues but configuration always has to happen to some degree. To help there maybe use file system snapshots (btrfs) to rollback changes.