I happen to know because I was once in a band and the only money I really ever received for our recordings after the label advance was from ASCAP. Even years later I get a check every few months for a few bucks, whereas I get nothing from spotify or any other music service (even though my music is on there).
So at least for me, I appreciate ASCAP and BMI, even though it is not a lot of money, they are the only ones who have ever paid me royalties as an artist - and their service is free to all artists no matter how small.