That's the idea. At least 2 copies, preferably on 2 different types/brands of media. Murphy's Law applies, things go wrong over time. I've had old stored hard drives fail after trying to extract data. I've had a big box of photos get destroyed by water damage; the negatives stored with the paper photos also got destroyed. I waited too long to attempt digital conversion of old 35mm video but the nitrocellulose of the film degraded and rotted. And I've had CDs and DVDs fail. I do have audio CDs from the early 1980s and they still work fine. But the type of digital CDs that people burn themselves are for the most part poorly constructed.
If you place your media in a home safe, place it in airtight bags with those silica gel desiccant bags, because home safes contain a lot of moisture. Best to vacuum seal the airtight bags; the machines are cheaply obtained. I vacuum seal a lot of old stuff to keep it from rotting. SD cards and USB sticks are pretty reliable, but even then I've had USB sticks fail. So multiple backups on different media is a good idea.
I’ve got to wonder if newer CDs will last as long as the older ones. Doesn’t sound like the music industry to actually sell you something that you don’t have to replace every 5 years does it? Of course, since I rip all my CDs to my computer, most of them only get used once or twice these days, so barring environmental issues, they should hold up.
One thing I’ve noticed about the older albums is that they really weren’t mastered that terribly well, I’m guessing because the engineers weren’t really as familiar with the digital format as they were with analog tapes. You can really tell when you rip the older stuff because you see some weird artifacts show up occasionally. For those, I’ll rip it to a raw file, and pop it into a sound editor to play with the levelling. It can make a big difference on the final audio files. In particular, whoever did the A->D conversion on the first 2 The Cars albums did a horrible job with the volume, like they didn’t realize the dynamic range of a CD or something.