My backups are tiered. Some stuff gets no backup at all, some gets even more than 3.And I tend to reuse HDDs that got replaced in my main machine due to size for my backups. Power consumption hardly matters when it only runs for a few minutes a day.

It is impossible to fully eliminate the risk but with a decent backup system in place it is somewhat unlikely to lose all of your data.

The 321rule should be used as a baseline. Your local backup should be snapshotted and somewhat hardened against ransomware (pull backups instead of pushing them, do not mount the backup volume to other machines). Cold backups also help.

Can I construct scenarios in which I lose all my stuff? Sure. But in those, we are either in deep shit anyway (CME, some big astroid) or it is pretty unlikely (targeted hacking)