Even if moral realism was true that wouldn't solve ethical dilemmas. There is a whole cottage industry in moral philosophy build around Trolley problem, other ethical dilemma thought experiments, and value pluralism which is not to be confused with relativism.
It is very important not to mistake hemlock for parsley, but to believe or not believe in God is not important at all. - Denis Diderot
We are the United States of Amnesia, we learn nothing because we remember nothing. - Gore Vidal
We are the United States of Amnesia, we learn nothing because we remember nothing. - Gore Vidal