Over the years, I've noticed that cassettes I recorded decades ago are still in better shape overall (not perfect though) than CD-R's I made up until around 10 years ago. Won't be making CDs of the new transfers, but will be archiving them on a couple of backup drives in both default WAV and converted mp3 formats.
I actually have a few PRESSED store bought CDs that have failed over the years, most recently the CD reissue of "The Button Down Mind of Bob Newhart". I have a few vinyl LPs from the late 50's/early 60's that still play fine, albeit for a few pops and crackles.
In other words, it is my personal conclusion, the old formats are FAR more reliable overall than newer formats. I can see why vinyl has been making a comeback!