I'm curious why a CD would not work anymore after listening to it a lot? Is the laser powerful enough to damage it or is it the heat from the device itself which is degrading the material in the long term?
In practice, though, it's far more likely that the the disc will get corrupted from small scratches.
[1] https://www.npr.org/sections/alltechconsidered/2014/08/18/34...
https://www.nature.com/news/2001/010628/full/news010628-11.h...
If you handled everything with white gloves and carefully moved the CD around it would probably last forever under a realistic scenario (you left it in a closet, didn't move it around much, etc.).
I have a bunch of original CDs from my first music collection that still work after ~20 years based on spot checking some of them 5+ years ago. Even with hundreds of playbacks.
But, I do have a handful of CDs that I remember having issues. They skip in certain spots due to artifacts on the CD. The real world happens. I don't remember what happened exactly in each case, but I'm guessing they got scratched. Like maybe I didn't put it fully into the black binder that held 200 CDs and I hit a bump in my car which caused the binder to jump around and an edge of the CD got clipped by the zipper, who knows.
Also burnt CDs seem to have a much worse shelf life. They are much more susceptible to being damaged. I don't know exactly why at a technical level but for sure I've had more burnt CDs fail over time. That becomes an issue when you want to back things up.
With mp3s, I can just put thousands of songs on my computer and everything works all the time. I never had an mp3 not play or skip unless the file itself was corrupt initially. They are also a heck of a lot more portable. You can put your collection on your phone, throw in some earbuds and now you can go on a run, or a 6 hour plane trip. You ever try running with a discman[0]? I have. It doesn't really work too well haha.
[0]: https://images-na.ssl-images-amazon.com/images/I/41305EZ51FL...