I have some QIC tapes that I backed up data to some 20 years ago (and a few DAT tapes for good measure). I still have a SCSI QIC drive that was working 20 years ago , but the data is in Novastor’s format and I imagine trying get the drive and software working to view it now would be an absolute nightmare. It there some kind of service where I could send the tapes and they could pull data off them. After 20 years have the tapes likely disintegrated to the point that trying to read them is pointless. It’s not worth that much to me, but there is nothing I know wrong with the tapes aside from being obsolete hardware and software.
Data recovery services can do what you want, but it will not be cheap.
They also say that it isn’t hopeless and the problem isn’t the data or the medium disintegrating (unless it was stored badly):
(ironically, they note that using a tape too often will cause the opposite problem)
Of course, operating the drive is a much bigger problem, perhaps find an old computer (IBM PC clone? ISA bus?) that can support it (I know that computers with ISA busses and the like were around long enough to use IDE hard drives, which can still be found today (or use an old drive, watch the capacity limitations of old computers though), including adapters for them, making it easy to transfer the drive to a modern computer; if you need software, I’m sure it can be found online somewhere).