Think about tape as an archiving tool, rather than a backup-and-restore tool.

(The three major tiers are A: I accidentally deleted a file or directory yesterday, so I need to get a copy from snapshots; B: the machine I was working on exploded, so I need to rebuild it and repopulate it with my data; C: archive for some need in the far future)

Suppose you have large quantities of data that you need to preserve for legal reasons -- it's always legal reasons, unless you are in academia or similar -- but you will not be accessing much. That's when you use tapes.

For most other purposes, you want a snapshotting filesystem or an offsite filesystem made from those snapshots.