I’ve seen enough edge-case failures to justify being paranoid about backups, even my backups have backups 
I still remember my first job out of school at 18 was to write a “decompiler” for a language I’d never heard of.
When asked “why” I was shown a large circular disk over a foot in diameter that was mounted on the wall, much like the “gold” record awards that you see in the music industry. This one was a metalic silver in color and had a lovely spiral pattern engraved into it.
“That” I was told, “is the platter from a 20Mb RL02 disk pack” and “the lovely spiral pattern is what happens when you get a head crash while it’s trying to retract the read-write head”.
“Ahh” I said. “Hope is wasn’t anything important”. “Well” he said “it’s the source disk for the custom accounting system used by one of the largest retail outlets in the UK”.
“Mmm” I said, “I guess you need to go back to a backup!” …
He looked at me quizzically and said; “that was the backup …”
Which resulted in a few us us spending the next year or so working on a DIBOL de-compiler, because all that was left was the installed binary … the moral of this story being, don’t tell anyone you can write a de-compiler 