I too have been finding music discovery difficult since GPM shutdown. YouTube Music is getting better at discovery fortunately, but I'm not finding multiple new albums/artists per week, more like 1-2 new albums or artists every couple weeks.
One of my favorite GPM features was the "concerts in your area", that is the only way I knew that some artists were coming through my city. It was one of the last features they added. The new album release feature was fantastic as well, although YTM has it now and it works pretty well.
Also, GPM would cache music locally on your device as you played it. If you were offline, you could just display explicitly downloaded music along with the cached music, it was the best for driving through the mountains or flights. If you were playing a playlist, it would cache multiple songs ahead of the current song, sometimes I'd get 30 minutes out of service before the music would stop.
I'll probably complain about the death of GPM for many more years.
