I'm saying you have a skewed idea of usefulness. Relative usefulness can only be properly evaluated when you look at the big picture.
The fact that you are not seeing the immediate usefulness of what you are doing does not necessarily mean much. Even a comedian can be incredibly useful if he helps stave of mental and emotional distress that could contribute to burn out or shoddy work among those doing the supposedly more "useful" work.
And yes I would say an artist or comedian is far, far more useful than a middle manager at a company managing devs fixing minor bugs on a website for a superfluous business. Back to my original point, I would probably give more to society as an artist than a dev. Some people would bring more to society as a dev than an artist, mind. In a world where we got paid just to be actually useful, there would be less devs and they'd all be better at their jobs.
A comedian, doctor, farmer, or teacher creates value. They directly produce something that benefits other humans.
The financial sector, marketing, sales, real-estate conglomerates, etc I see as value movers. They don't actually create something themselves, but rather move it from someplace else to themselves, thereby forcing others to play the same game not to get outcompeted. It's pretty hard to argue marketing or hedge funds aren't a zero-sum game.