Earlier quoted context omitted.
What is unsolved? What's the revolutionary change since Winamp or Itunes in 2003?
I love and still use WinAmp and do not use any streaming -- but what changed is how people listen, thanks to iTunes and iPods etc and then Spotify. Everything is based on playlists and artist selection leaning away from albums/releases. It changed how people load up music, introduced a huge rise in 'random' playing that was way different than previous era of CDs where you'd pick an album and play it, or listen to rad…
Everything else is an addition, but somehow modern apps have managed to make the basic grid worse too at the same time.