That's why I try and used both - I'm also throwing a copy onto a USB thumbdrive if its important stuff.I have more faith in optical media than mechanical media (I have a box full of dead hard drives). I have lost one CD due to failure in 15 years (and I could recover the data with CD Diagnostic)
Digital photography lends itself to being backed up so the more the merrier. I just wish bandwidth was as inexpensive as it should be so I could throw a copy up into the cloud too.
BTW - you're lucky to have only lost one CD/DVD to corruption . . or maybe I'm just exceptionally unlucky.