i think that's it. We used to use CD-Rs and DVD-Rs to record playlists and movies, respectively. Data hoarders today will prefer multi-hard drive servers over burning everything to Bluray, and for one-time file transfers, we have flash drives and online file shares. I just can't think of a use case for BR-R that isn't better served by a different technology.
When the tape drive fails and eats your tape in the process, you better hope you have a second backup or you'll be crying salty salty tears.
I worked in the service center for a tape-drive manufacturer and I would routinely see the drives we got back for repair. They were often taken apart by the customer in a frantic and desperate attempt to get their cassette out. The cassette was almost always still in there though, with multiple feet of tape snagged and wound around everything.
Presumably when we're talking off-site backups we're talking about a separate company sitting somewhere in an abandoned nuclear bunker which can justify the price of a tape drive or twenty.