I am a heavy user of spotify and their "station/radio" feature. Like a song? Go to it's song-station and explorer other songs like it.
It's this kind of discovery that keeps me using Spotify.
I think Bandcamp is neat just for having users' purchases be default public, so I can click on user profiles of people who bought an album and see what other albums they bought. Admittedly I don't discover much this way but I do like the Bandcamp weekly radio shows. Probably the highest density of finding new artists was back when I listened to XLR8R podcasts... Wow I just went to see if they were still around only to find they shut down like last week
I'm a Qobuz subscriber now but the auto playlists let me down more often than not, totally changing up the genre of whatever album just finished. Hard to beat their drm free lossless catalog tho. I think nowadays my primary method of discovering new music is Shazaming tunes in hip thrift stores whenever I visit LA or NYC
In Apple Music I look forward to the playlist of 100% new (to you?) songs that it offers every Friday. The Discovery station is usually good too, but I find more keepers from the Friday playlist than others usually.
Bandcamp is definitely the best for finding completely new artists and genres though, for me at least. Something about their featured “New and Notable” posts makes me willing to just try a new genre or artist, much more readily than other services. And I strongly agree on your point about user profiles being public. The “what’s your favorite song on this album” and “why do you love this album” text fields that you can see all over are full of comments that are just wonderful.
FWIW, other services like Apple Music and Amazon music (I’m sure others as well) also have similar “station” like features, where you can play a station for a given song/album.
Apple Music will also recommend songs at the bottom of your playlists that it thinks fit in, which I find is another great way to discover music.
I think the play-a-station method of music discovery has been around for a long time. If I remember correctly, even old iTunes used to have Genius(?) which played similar songs from your library.
Are there any alternatives to that?