It depends on the dye used. Older CD-Rs had a really bad dye formulation. Better formulations were created but most of us just bought blank disks based on what was cheapest not what dye was used.
Even the newer ones will still degrade quite rapidly in direct sunlight, so the method of storage is also important (spindles in your bookcase that get hit by sunlight = bad).
FWIW I archived all my CD-Rs and DVD-Rs when the oldest ones were just about 15 years old and aside from one ultra-cheap disc where the top was literally flaking off they all read fine in ddrescue.
I was part of an effort at my last job to archive some of the source code for our oldest projects(from the 90s), they were all on CDs stored in a vault with an external storage company, we retrieved the boxes and found that 1 in 5 discs didn't read at all. The blue verbatim discs had a 100% success rate, but any disc with that green hue underside was a toss up whether it would read or not. Interestingly though, over hundreds of discs I found that either the disc read and would rip correctly all the way, or it wouldn't work at all in the first place.
Practically all the CD-Rs I burned on good media have lasted over 20 years now. Only a few have had noticeable issues of the ones sold as "archive-quality" media.
Sure, almost all my cheap ones have died out, but even some of those are still pretty OK.
