i cannot fathom how your example here supports the idea that Bieber playing 24/7 in a gym is stealing money from the niche artist who are listen to by only a handful of fans?
You, who listen to IndieBand™ for a total of an hour a week or so.
The Gym™ who plays Bieber 24/7 every day, all month.
You each pay $10 a month, so $20 total. Spotify allocates based on plays, so Bieber gets 720 "played hours" and IndieBand™ gets 4. So Bieber gets 720/724 of the $20.
The OP is saying in this case, Bieber should get $10 and IndieBand™ $10 (minus fees, etc).