Utilitarianism Wins Outright Part 21: A Piece of Moral Data That Other Theories Can't Account For
I think this is a pretty good argument
I got the argument from here. The video was very long so I thought I’d summarize it succinctly.
Other moral views have trouble accommodating the moral intuition that if X action makes everyone better off, one should take that action. Utilitarianism provides a neat account of why this is true, while other theories have to either deny this or stipulate other things.