I used Play Music as my primary music player on my phone to play the 64GB of MP3s off my SD card.
Now with the release of Youtube Music, Google has decided to break all Play Music functionality, specifically:
I can no longer tell my car's Android Auto to "play music" to pick a random song, it now says "playing music from Spotify" (which I don't have)
I can no longer tell my Google Mini to "play The Beatles", it now says "You might like this great Beatles radio station on Youtube Music!" (I don't)
All I need is an MP3 playing app that works with Android Auto, Google Home Mini, voice commands, and supports things like playlists or playing an entire artist, or playing all 64GB of MP3s on shuffle.