Re: Long live tape !
You may have been working in IT for 25 years,but you obviously have no clue what you're doing if you can't even manage a proper backup and restore with a tape! The bare minimum for an IT person who is in charge of backups is to actually verify that they can do a restore, if they cannot then they start troubleshooting, calling support, whatever they need to do to find out if the problem is hardware, software or IdioT related.
What do you tell people who want a restore, that it isn't possible because you have never figured out how to successfully restore anything from tape? Maybe you are using disk based backup like a Data Domain, but if you still have tape drives and use tapes you need to figure out how to make them work (or have them fixed if the hardware is faulty) and not just assume that because you can't make it work that "tape can't be read after it is written".
If tape wasn't actually able to be read, don't you think people would have caught on by now and quit buying them? Do you really believe that no one ever needs a file restored, so they just haven't caught on to something you are "smart" enough to have figured out? If someone said what you did during an interview I'd stop him right there and thank him for his time, and figure he was a poser with a fake resume who had no clue what he's doing.
As for the comment above that SSDs will replace tape, because technology changes over a decade means you won't have equipment to read those tapes any longer. Have you ever tried to read an SSD that hasn't been powered on for a couple years? I think you'll find it has lost all its data. It is not useful as an archive medium unless it is kept powered on. If you can afford to keep your "archive" SSDs powered on, more power to you, but for a tiny fraction of the cost you could afford to pay a tape monkey to insert those tapes into the library and copy them to newer formats every few years to insure you don't have the problem. Or simply keep a few older technology drives in your library (if you have one of the huge ones) or keep an old library with the old drives (if you one of the small ones)