Tapes decay so it would still be irresponsible to have only one copy of the digitized versions. It's still possible that they have other copies though that are just harder to access.

NASA stored all the data from space missions on tape - those old reel to reel mag tapes like you see in old SF movies. Decades of using floor buffers ended up erasing the bottom 2 rows of tapes.

https://www.ibm.com/history/magnetic-tape

Usually what kills the tape is the little reflective stickers on the back side of the tape material will fall off and render the tape useless since the machinery can't tell where the recording starts. Apparently I bought cheap mag tapes back then.