I accidentally untarred archive intended to be extracted in root directory, which among others included some files for /etc directory.
I went on to rm -rv ~/etc, but I quickly typed rm -rv /etc instead, and hit enter, while using a root account.
That or make your system immutable
You can still break your /etc folder. But many other folders are safe.
Personally I do both.
Use Nix. And keep your system config in git.
That’s my current approach. Fedora Atomic, and let someone else break my OS instead of me.