Nothing

• You can import music from itunes, if you like doing it the old way.
• There are a crap ton of media player apps with ability to connect to self hosted or cloud storages. Many are single payment and others are open source. One good one is nPlayer.
• You can put mp3 on the native files app and just tap on it.

The article is just misleading ragebait turned into an excuse to show their app and things about iOS development.