Agree to that.
I have dumped most of my old DVD-Rs and CDs now, because they had old information. I had problems reading some Verbatim DVDs but it was still only a few parts, over all the discs where good. And none of my older CDs had any problems.
The thing is, if you have pressed cd's, music and so on that you bought way back in the day, all of them are just fine. As long as you store them right you will have no problem. Burned discs is a different story. But I would say that old CD-Rs are way better than DVD-Rs and bluray is the worst, at least the disc you can burn your self.
If you buy quality gold CD-Rs to burn stuff onto, you should have no problem trusting them for 20-30 years, they will hold the information without degrading, that said, it is wise to do a new copy every 10 years just to be on the safe side. And you also have to burn the discs the best way possible to maximize quality of the burn.
As long as "The US Library of Congress" distributes backups (pressed discs) and save stuff on tape. They should be fine.
Best storage is however books, printed paper. But the question is, how long do you need to store old data, books tend to not store data in that way, they are more of a information bank.