Spotify is a middle man.

Of course they are paying out the majority of their revenue to the people who are actually responsible for making the music i.e. the artists and the labels who represent them.

And it's legitimate for artists to criticise the lower per-stream royalty when they see Spotify paying people like Joe Rogan pretty exorbitant amounts of money. And when many of them aren't signed with large labels but are instead going through self-service labels where the artist collects most of the royalties.