I can’t remember any portable MP3 playing device before iPod that wasn’t a joke. Are you thinking of a particular product that was comparable? I’m curious.
Apple fixed the experience for non-nerd. Instead of having to go online and find music files yourself you could just go buy them.
If all we're working with anecdata, I honestly don't know anyone who didn't have an mp3 collection before the iTunes store.
The tech for the first iPod (Firewire and a 5GB hdd) made it essentially a different category of device.
Everything about it sucked ass, including transferring songs over serial.
[0] https://images-na.ssl-images-amazon.com/images/I/D1afoHzHkMS...