I would argue a Diskman was decidedly LESS convenient than a Walkman—sure it had neat “skip” functions but god—optical disks are probably one of the worst media formats to have ever been created. (Maybe—just maybe—from a functional standpoint MiniDisk was okay, at best)
I miss iPods. It would be nice to have a tiny device to use with Bluetooth headphones during workouts and running so that I don't have to carry around my phone.
A smartwatch could probably fill that function, but they're so expensive because of all the health crap they load them up with.