Death very much depends on the specific media and how you treated them. I've got loads of CDs from the 90s that are absolutely fine. I've also got ones I've burnt in the late 90s, which have completely delaminated into a clear disk and and a piece of foil. I don't think I've had any pressed discs that have rotted.. but only time will tell (I suspect Laserdiscs were fine, until they weren't). You can pick up archival BR disks though, if you're concerned about longevity. This is what you're concerned about, right?