The artists and music companies decide themselves to publish there.
It might be interesting to read the fine print before doing so.
And no, not everything that is published gets a lot of listeners.
Same as with the radio, most songs don't get any airplay at all or only at more specialized stations with 0.5 listeners on average per hour.
Every Friday I get a new list with new released singles. 90% of that has very little potential to attract a lot of listeners.
I think radio stations are far more suffering from streaming services.
If I'm not in the mood to handpick numbers, Spotify takes over and lines up song after song that I'm interested in.
They do a lot to keep their listeners happy, and rightfully so, They take our money,