Many tape vendors claim tape has a shelf life anywhere from 10 to 30 years. With over 20 years of real-world experience, we have not found this to be the case. We have been unable to find reliable statistics on shelf-life for data stored on tapes or hard drive backups, yet we believe the data stored on a High Rely drive will last at least as long, and probably longer than data stored on any type of tape.
This can be said because hard drives are hermetically sealed and have rigid surfaces with very even distribution of magnetic material. Tape drives have a surface that is flexible, uses very cheap plastic substrate, becomes brittle in sunlight, and is openly exposed to the atmosphere. Even if the electronics failed for some reason, data recovery companies often pull data directly from hard drive platters.
Hard drive data life is usually quoted at 3 to 7 years. We have experience with many drives that last longer than that.