Plus with general wear-n-tear, the average CD gets scratched and then becomes useless.

Microfilm would still be viewable if it was scratched a bit, and they get a lot of abuse from users. If they could use MO disks similar to that used on Mini-Discs, then it would be no problem. Mini-Discs can't be harmed accidentally. I know there are some computer M-O discs and drives, but the field is in its infancy. Speed and capacity have to be improved upon.