The tape obsolescence problem
I've seen some of this myself, back when I was involved in tape duplication and conversion. Writing the software to read, write and manage the data was the easier part. (Most of the time—getting technical documents from hardware makers took a bit of hoop-jumping, while data specifications were sometimes closely guarded.) The hard part was keeping the tape hardware working, because they were being used a lot. The people who know how to repair and maintain that stuff are mostly retired now.
DAT (Digital Audio Tape) and LTO both had long lives, but DAT faltered and fell away in the 2000s, and the supply side of LTO has shrunk in recent years. All the other formats—reels, Exabyte, DC (Data Cartridge), various proprietary formats—shone briefly but fell by the wayside.
And all physical media degrades over time. Not just tapes, opticals disks can succumb to bit-rot too.
I'd imagine that, much like data recovery from hard disks, you'd have no guarantee that anyone could retrieve precious data, even if they had the tools to do so.