Optical is good, early CD's had failures of the coatings and the reflective plate would oxidize, but their main problem is low capacity. Tapes are in the 16 terabyte per cartridge range, but yes, I still find old VHS and cassettes which makes me cringe.

One thing is no matter what you store your stuff on, one day it will be obsolete. Always good idea to migrate the old archives to new storage once its technology settles in. 

I'm kinda a hoarder of old computer hardware. Can't really sell it for more than scrap, so if the space allows I'll keep it for some future use. For a while I was making some profit selling the old stuff, things like floppy drives (8") and even Zip drives. Always someone out there that is desperate to recover a box of old stuff and don't have the hardware to do it.

Hard copies are analog and wonderful, though bulky storage. A document can always be rescanned. Photos too, but being digital, everyone has 1000x more that when you had to pay to get them developed.