What tape has over hard disks is simplicity.
Yes and No (mostly "No"). Although a tape cartridge can be a physically reliable device; tape drives (except perhaps at the extreme high end) are typically not. Further, they often evolve in not-backwards-compatible ways.
A disk drive contains both the media and the mechanism. It typically costs 2x as much as tape EVEN IF YOU CONSIDER THE WHOLE DRIVE THE MEDIA.
Tape drives, on the other hand, are expensive and touchy beasts where the moving parts are exposed to air and dust.
Further while the mechanism to read the tape involves some kind of fairly standard interface that doesn't change all that fast (e.g. SCSI, IDE) the tape itself tends to evolve. Reading a first generation 8mm Exabyte tape isn't even possible on recent tape drives (is that format even still in use?).
A disk more typically needs to have some kind of format that's still around, power and a standard interface (SCSI, IDE) and that's it.
This means the total system: tape+drive is less likely (in my opinion) to be available/documented/repairable than a disk drive.
I've read 20 year old tapes and 20 year old disks and neither was a pleasant experience....but I'll take the disks. Especially if I have a lot of the same kind of disks (for parts). Also, I suspect less magnetic leakage since in a tape the magnetic regions are close to each other in 3 rather than 2 dimensions.
Reliably reading 50 year old tapes for any reasonable amount of money is, again in my opinion, something of a fantasy. Same for magnetic disks at that age although I have hopes for DVD-type media....but I am not an expert in archive media, just someone that actually has to read the stuff.