Not so related, but I actually like Spotify’s algorithm for suggesting new music a lot. Currently my daily routine for discovering new music is 1) pick an album that has something to do with what I want, 2) start the last song in the album, 3) skip it. It works pretty well!
I think this gives you similar material to the Song Radio functionality. You could use Album Radio or Artist Radio as a shortcut. I use these and Discover Weekly to discover a lot of new tracks. I know some people don't find discovery via Spotify to be useful at all, but like you, I think it's excellent. I've come across thousands of new tracks, and their strike rate for suggestions is generally very high.
It might help that my bar for favouriting a track is as background noise for the office or around the house rather than purely 10/10 killer desert island tracks.
