If you make a git repository on your machine and then delete the entire directory it is in you can not recover it despite git being DVCS. If you have 2 forks of the repo stored on the same disc as the upstream repo and that disc dies, you lose everything.
I'm paying homage to the saying that "RAID is not a backup." In a technical sense RAID can create a backup of each block, but that is not what people are referring to when they say that phrase. They mean it as a backup as one may need for disaster recovery.