Agreed, backups are important. Before switching to NixOS (or image based OS like Fedora Silverblue) I made use of automatic btrfs snapshots. This makes these kinds of screw-ups simple to revert.

I'd like to say an overly optimistic chmod -R didn't happen again but my old Nextcloud instance would like a word.

Thanks for reminding to do my backups again. I've recently build a server with enough storage so I'll probably setup restic or borg. That means I can bring my external backup HDD over to my family as an offline/offsite backup.