I thought making backups before breaking things is a natural step to do.Imagine having a production machine go down with no good way to restore things other than a complete reinstall from scratch or a good handle on ZFS snapshots. If it's a non-production machine that you don't mind spending time on, sure, go ahead, practice, make mistakes, and learn. But if your job is on the line, you gotta make damn sure you can put things back exactly as they were if the change you introduce does not work out as intended. And if you can't do that, just leave the machine alone.
Sure you can use ZFS snapshots, but machines don't having snapshot capabilities could do a complete sync of the machine with rsync for example.
Another step would be doing a backup file before editing the source in the case you really break something.
If you update you could create a boot environment backup in case.
With the necessary precaution steps breaking things shouldn't usually be that harmful as you should be able to restore the state previour to changes.