I can see Utilitarianism being a useful guide for people who don't constantly think of how their actions affect others.
As someone who has anger issues, I often want to say or do something to lash out at those who have hurt me. Even though the action is legal (and sometimes justified) I have to stop myself and think of the suffering it will cause versus the "pleasure" it will bring me. As I have gotten older I realize that the temporary satisfaction I feel (which is soon replaced by guilt at causing suffering) is not worth what it causes the other party, no matter what harm they caused to me.
Reading both John Stuart Mill and Rachel's chapters on the topic I think that the forms of Utilitarianism explored are mostly at odds with capitalism. My experience with capitalism is mostly as someone who would be categorized as lower class, and it is a system that puts growth (especially unsustainable exponential growth) above all suffering unless that suffering is bad enough to create public relations issues that may affect profits. Obviously not all corporations or capitalist governments are absolutely ruthless, but overall the system withholds vital resources* from those who cannot afford them.
Insulin's High Cost Leads To Lethal Rationing - https://www.npr.org/sections/health-shots/2018/09/01/641615877/insulins-high-cost-leads-to-lethal-rationing
