Spotify pays poorly per play, but per play is a rotten metric.
Payout works the same (all subscription fees are pooled, then paid out according to total plays) so music services are "punished" according to the payout-pet-play metric for connecting people to the music they will listen heavily to.
The best services on on this metric, will be services which most subscribers don't even use - maybe because they don't even know they have it because they got it bundled with their cable TV etc. Obviously this is not sustainable or desirable.
I have sympathy for artists, and little for Spotify. But it's also artists who are primarily responsible for the authoritarian copyright mess we have today, from Sonny and Cher to Jean-Michel Jarre to Metallica. Not sure I like the revolutionaries more than the old regime. Especially when they push garbage metrics like payout per play, and their most usual solution boils down to "you should pay me, not all those others you listen to" or "you should listen to less music besides me".