Personally I would argue against using CD-R or other optical media for long-term archiving, with the possible exception of the Mdisc system. I've seen many studies also not recommending CD-R archiving.
Briefly, beside the capacity being pretty low these days, there are several different construction and chemical dye methods used with different stability, optimal burn speeds and durability. Some seem to last pretty well, some become unplayable after a day in the sun in the car.
The data integrity is not so great, especially for audio CD-Rs. Audio CD-Rs can burn with no indication of burn flaws/data errors. They will also play back or rip with no indication of these errors. Listening/watching is not a good indicator, as it depends greatly on the error correction and concealment of a particular player, and it takes a lot of time and effort. Data CD-Rs should be better for checking data integrity, but it seems the failure mode is that one day, it simply does not read at all.
The standard for checking optical disc integrity is to analyze the error rates. At work, we used the Clover Systems CDX analyzer, and now we use Plextools. These analyze, tally, and chart several levels of correctable and uncorrectable errors on a disc (as your player would encounter), faster than real time. I have an audio CD-R burned in 1990, and it still analyzes (and plays) fine today, but I have other CD-Rs much newer that no longer play. The 1990 CD-R is a Taiyo Yuden, and when I got it in 1990, I was told the blanks were about $50 USD each.
What to do? To be honest, my Uni still makes audio CD-Rs on MAM Gold blanks but only for convenience, and we are not relying on them for long term archiving even if they claim 100 years. Mainly because of the amount of data we generate, the recommendations from the likes of the Library of Congress and others is to use computer storage systems (hard drives/tape) with triple redundancy or more, and SHA hashes for checking integrity after regular recopying of all data. There is still lots of controversy about the whole archival concept.