I guess that depends on how often you play them. When I was young I played certain records and cassettes so much they wore out and/or lost sound qualilty pretty fast. For that type scenario, CD's are a pretty good medium. If you are just going to store them in a drawer, then not so much.
CD lifespan loss isn’t from overplay, it’s from oxidation.
Periodic backups is a time consuming and costly process. Then there is the whole “verification” of the dupe. And the storage...
Scratched records will still play. Dirty records will still play.
90 years later even.
Playing them more or playing them less isn’t the issue, since the information of the layer on the disc is read through the polycarbonate substrate. What is at issue is the reflective layer comprised of aluminum will oxidize if exposed to air, which is why the top of the disc is sealed with an acrylic layer (in the early days we used solvent based lacquering materials and then switched to UV based material for both environmental and cost issues). So depending on how what type of environment the disc is exposed to over it’s lifetime (humidity and temperature) it could last for decades.
3M (later Imation) was offering a product that guaranteed 100 years for archival purposes that was more expensive than other CD-ROMs at the time.
In any event, with the cheap cost of external/portable hard drives today it would be silly for anyone to NOT backup their CD’s on those drives and then burn copies if their original discs ever deteriorated beyond playability.