Few years back, when employer was using tape backup, 3000 tapes per back, I was advocating changing. Told them that even with a 99.995% good rate, there was still going to be bad tapes. Nah never happen.

Did a Disaster recovery test. Had to go back 3 or 4 weeks of tapes before we found a complete set...

Much better now, still long way from what I'd call reliable.