MP3 players are obsolete ever since Spotify convinced everyone that managing a personal music library is too much of a pain. Maybe this is about Shoutcast.
I continue to maintain a local MP3 collection and use a local MP3 player. The main reason I haven't tried out more streaming services is that most of them require Adobe Flash which doesn't work well on Linux. The secondary reason is that streaming libraries often lack specific content I want.
The tertiary reason is that I have no internet in the subway.
The quaternary reason is that I still have the music I bought, even if the company provides the streaming services goes belly-up, decides it won't support my country any more or even just has a bad day or an outage.
Depending on which streaming service you use, possibly a non-issue when you can simply cache whatever music you want for offline access.
There'll be always music which isn't on Spotify, actually quite a bit I listen to. And besides of that I also think really "owning" the files has ethical importants to it...
I didn't need much convincing.
I always liked that aspect, so I still haven't switched. I'm sure there are weirder hobbies out there.