I was recently doing a little purging to "spark joy", and some of that purging included backups on optical discs (CD and DVD) that go back more than twenty years.
I'm a little ashamed to admit that I am a bit of a data hoarder, but I'm getting better.
My general feeling now is "if you haven't looked at this in 10 years, you're probably not going to miss it." In any case, I separated my optical disks between data and non-data (e.g., very old software installers, etc.) and still decided to review the content on the optical discs just in case there were some things I'd want to retain.
The one hard lesson that I learned was that not all opticals survived the test of time. The non-surviving opticals saved me a lot of time in terms of review—sort of, but not when you consider how slow optical discs are to read— but they did cause me to rethink my use of opticals as a backup and archive medium.
To be fair, the cheaper the optical discs that were used, the higher the likelihood they were to fail. Having said that, many branded opticals had failed too. Some discs worked on some drives, but failed on others (I was using two different drives on two different computers to try to get through them faster).
But an even bigger problem, is that opticals have, in a way, become a bit of a dinosaur. Unless you have a wallet teeming with cash, tape drives are priced beyond the reach of most small businesses and consumers. Blu-Ray writables provide a somewhat affordable method of cold storage, but my experience with them have been hit or miss.
Another conundrum? How do you destroy an optical disc before disposal? There are many shredders that can shred a CD, but it is a bloody mess. You will end up with tiny shards of sharp plastic and glitter flying all over the place. I discovered that wrapping an optical disc with saran wrap reduces the flying crap produced by the shredding process. Also, some of my older discs (namely Maxell CD-Rs) would jam my shredder.
There used to be a device that would emboss the readable surface of a disk, but they're no longer in production and hard to find. I guess you could use a sander, but the dust particles produced by that probably isn't great for your lungs.
If you have a lot of discs to destroy, I would suggest buying a cheap, secondary shredder (to avoid ruining your paper shredder) and a lot of Saran Wrap.
It also sucks that where I live, there's no way to recycle old writable optical discs. They're basically destined for landfill.
Going back to the offline backup issue, however, what is a person to do? Well, there are cloud services. Using something like OneDrive, Dropbox or something similar is a good way to back up, since they tend to be a relatively frictionless way to get your data in the cloud (and offer a little protection from ransomware attacks). External hard drives and SSDs are good, but you have to remember to disconnect them from your devices, lest they be exposed to a malicious attack or catastrophic user error.
I still wish there was an easy and affordable solution for offline write-once-read-many high capacity removable media backup, but alas, there's simply not enough demand to make that happen.