Despite whatever revenue model(s) are employed, every song that is played generates a fee for the host. Generally, popular media come with higher fees that cost them more to stream, while less popular media are cheaper to license and net them more. The algorithm tries to increase the margin that comes closest to their perception of your preference(s). In theory.

I find it pigeon holes me into a category that may or may not appeal to me, and I get to listen/view what they want me to experience, rather than let me choose & explore without manipulation. No, thanks, is my response.