Things that are cool about minidiscs:

- tactile physical objects
- can record them to make mixtapes like cassettes
- but the music is digital and doesn't degrade
- can re-record them essentially infinitely
- durable and relatively small/portable

has some of the benefits of modern digital music like...
- disc/track metadata
- shuffle/repeat
- multiple encoding options for flexibility in how much you can fit on a disc
- they look cool as hell