|DVD's and CD's go bad much faster than originally claimed.|
The data is on a chemical dye. It goes bad for a number of reasons.
Also the burner you used 10 years ago might be slightly off from what you have today.
Try them on different systems both new and old. One of them might recover the data. Move to a external usb hard drive or two.
Why did it take me over a year to phone in a problem to ATT?