Recently I read an article about how generally speaking it's very difficult to keep data around for more than 10 years; this is something I'm already very well aware of and have been for a while now.
Old data is something that can really sneak up on you. Over time you download a whole bunch of stuff, then one day go to check how much stuff you have and realize the total of it all is frappin' huge. At that point you either stuff it all on a big external hard drive or a bunch of DVDs, store it away and forget about it until needed at some point in the future.
As much as I hate optical discs, I do prefer them for long-term storage. They're convenient because you can place discs in a book, stack them in separate paper sleeves or jewel cases, or even restack them in a spindle. Any way one goes about it, there's nothing else that comes close to discs concerning physical convenience. Standard USB sticks can't be stacked. Hard drives whether bare or in external enclosures are bulky and heavy. Tape? Pff.. who uses tape? In the end, one is just better off using discs and that's why I bought a 100-pack of them a few months back, because the other options just plain suck.
And don't even tell me "put it in the cloud", because that's a joke. There is absolutely no guarantee the data I push out there will be there in 10 years or even tomorrow; this is why with Dropbox I only use it sync-style and not cloud-only so I have two copies (local and cloud).
I used to question why anyone uses DVDs for data storage, but now I don't because as crazy as this sounds, it is the best option. If they're stored proper and accessed using a good drive, DVDs can last for 10 years. Maybe even 20. Maybe longer. They can also be sorted and stored out of the way easily.
Ten years from now, it's totally possible nobody will be using optical media anymore and no new computers will be sold with them. That's fine because if there is one thing I can guarantee, you will be able to restore a retro PC in 10 years with that optical drive in it, or at bare minimum be able to connect an external optical drive to get your data back, then use a virtual PC to access the data if need be. All of that will be totally do-able. How do I know this will be so? Consider for the moment that you can still buy a USB floppy diskette drive on Newegg - and floppy disks too if you need them! All brand new! Why do they even bother selling that stuff? Because there's enough demand for that ancient media format even though no new computer is sold today with a floppy diskette drive.
If the floppy drive can last that long, just imagine how long CDs and DVDs are going to be around.