I think people get distracted by the "percentage of revenue paid to musicians" thing, when the bigger reason streaming pays out so little to artists is that people pay $10-$15 per month for unlimited access to all music. Even 80% of that, split across dozens or hundreds of musicians, is not very much. Of course, it's also worth remembering that streaming was partially a response to widespread piracy. It's difficult to get people to pay very much at scale for easily copied digital media.

In addition, a greater share of the payout (relative to number of streams) goes to big music distributors that control the biggest, most popular artists and have the leverage and employees to negotiate those agreements.

It's not evenly distributed. Big labels get much better payouts per listen than independent artists