If music discovery faces an inherent problem, it’s that most people stop looking for music after their youth.
Spotify et al. offer catalog music for the most part. If you want to hear new music you need to hit the blogs to stream music via SoundCloud, Youtube, or uploaded MP3s.
But lack of content is not the sole challenge for the music seeker. Music discovery is a human art form that can’t be discovered through a Spotify or Pandora algorithm. No one really likes music until those who know it best show them. These are the DJs.