Bandcamp is US owned, but still worth mentioning I think because of their commitment to high revenue sharing, about 80-82% goes directly to the artists. They have custom playlists, and offer high quality formats as well.
If the goal is a quality product and an ethical approach to supporting artists I'm not dead set on only using European alternatives
About this, I will try to find it. But there is quite some research that shows productivity in simple jobs (think assembly line, or fruit picking) goes up in relation to reward. But complex an skilled jobs actually give diminishing returns quite soon with a higher reward, because with complex jobs most of the satisfaction comes from doing the job itself and excelling not the reward.