Optical discs are not really meant for longterm storage on their own. Disc rot is a real thing.
Edit: I should have gone into a bit more detail. Yes, optical storage discs CAN be okay for longer term storage. But it depends on quite a few factors. The material itself has to be long lasting, the manufacturer has to have good quality control, and the end client should store it in a controlled environment. It’s it better or worse than alternatives. No idea without the actual data. It certainly has better density.