Backups and a tested process to recover assuming you damage your server beyond repair is a good thing to have. It's unlikely, but you would look foolish not to have this sorted before you press the button.
You could always re-install, but then do you know all the packages and their configuration updates? You would have to re-create all the users, ssh keys, all sorts of things to communicate with other servers etc.
Not that I'm paranoid, but I'd prefer not to get the sack if I can take sensible steps first.
Robin