So true, but I’m not sure what I could have done here, except stay on iOS 12* indefinitely. This wasn’t a case of having an invalid backup per se (I was able to restore my phone back to iOS 12), this was a case of being unable to port forward data from iOS 12 to iOS 13. In other words, a perfectly working system could not be upgraded via Apple’s upgrade process, nor did Apple provide good workarounds for this scenario, such as allowing the restoration of individual apps.
That’s why I’m extra disappointed in Apple. I did everything by the book, including testing my backups, and my data was still lost.
I think what you can do now is avoid complex, binary, and/or proprietary formats for your data, because they are more difficult to back up and restore.
You can also learn to not trust software which promiess you the world, but doesn't let you see its internals.
Yeah, lesson learned. Fortunately my most critical data was backed up elsewhere. This seems like an inherent issue with iOS, I will consider migrating to a different platform. Any suggestions other than Android?
That’s why I’m extra disappointed in Apple. I did everything by the book, including testing my backups, and my data was still lost.