Absolutely, but this is also true in other publishing industries. The narrow top takes most of the pie. Charts, trending, top 10… and so on play a big role in this concentration.
If a stream pays between 0.003 and 0.0075 USD one quickly see the amount of streams needed to earn a minimum wage. Add to that that the artists only see a portion of that income based on deal. (Roughly 50% to all creative involved, 50%)
The users pay more per stream on average, as the platform takes its cut.