I would just like to know why there is a need for a distributor in Indie Spotify artists? Its an agent. This agent doesn’t do anything. I make music, I own all

I would just like to know why there is a need for a distributor in Indie Spotify artists? Its an agent. This agent doesn’t do anything. I make music, I own all rights, I upload to streaming service, I should get all cut from streaming service. What does said agent do?