Google Play Music also allows you to upload your own music:
>You can add up to 50,000 songs to Google Play Music from your personal music collection using Google Play Music for Chrome or Music Manager (up to 300MB per song). Once you've added your music, you can listen to it through the Google Play Music app and on your computer.
I've used this for years but moving away to use Plex as Google never seems to have figured out reliable caching.
Syncing to device offline is fine but Google music often seems to crap out streaming between songs on Android and iOS and I'm stuck skipping tracks or having to restart playing.
Never had issues with Spotify, plex, tidal, or Pandora in this regard.
>You can add up to 50,000 songs to Google Play Music from your personal music collection using Google Play Music for Chrome or Music Manager (up to 300MB per song). Once you've added your music, you can listen to it through the Google Play Music app and on your computer.