A CD is like a DVD with only sound. A DVD is like a Blu Ray but can't hold as much. A Blu Ray is what your PlayStation/Xbox games come on. Given the popularity of game consoles and that most of them still use optical media, I don't think CD/DVDs are things that a young person would be unfamiliar with. Unlike floppy disks which have no equivalent or use for average people these days.

No love for MiniDisc data or Zip Drive :(

Me neither!

That's kind of horrifying in itself, considering I don't think there's a viable alternative for (WORM) mid-to-long term data storage most people have access to.

Of course, in practice with optic media you may stumble upon varying forms of bit rot, scratches or recording errors so it's definitively not the be-all and end-all, but still, I've got CDs recorded 30 years ago I can still read in modern systems and that I won't wipe by accident.

Blu-ray's are still reasonably common, though they are slowly disappearing as well and I don't think there will ever be a successor. Fact is that write-once read-many is just not considered a very valuable property by itself, and as rewritable storage is becoming cheaper (if only by economies of scale) it'll displace them.