There is a tool called qrazy box
https://merri.cx/qrazybox/
It allows you to essentially remake a damaged or partially hidden QR code pixel by pixel, but has some limitations.
Depends on the situation. It also depends on how sentimental a person is for their data or information needed in a given situation.
If a cat shows up on your doorstep and now you got to figure out who owns the cat because you become concerned about it over time, what do you do if you can't scan the QR code on its collar?
Of course it depends on the situation. Almost everything "depends on the situation".
The point is that in general, QR code content is less important than hard drive content. And that (the low demand) is the simple explanation to why there aren't as many tools for recovery.
It would probably be nifty for pet owners if, instead of putting a QR code on something that is known to wear, we came up with something a bit more resilient. Maybe something that could be permanently affixed to the pet in some way. Perhaps even under the skin. And it could even be powered by the device that reads it.
Basically, we put data into QR codes the same as hard drives. Why then are there so few data recovery tools for QR codes?