This is true, but on a personal level I have no idea how to do the calculus for, “My work is killing people, but it would have been worse if it hadn’t.” I think the show “The Good Place” got it right and it is just too interconnected and complicated to actually derive an answer as to whether an action is net negative or positive. That said, if I had to place money on a given action being negative, working for an arms manufacturer would be one I’d be fairly comfortable betting on.