Eventually you have to weigh one instance of pain against another—that’s where the subjectivity is more obvious. Can’t be measured.
Objective means external. All moral systems other than divine command originate internal to humans.
Yep, it might come to that point. No one ever said it was going to be easy.
But appealing to a Creator doesn't add anything to the process, especially when the translation of the Creator's wishes is so contradictory, and mostly archaic. Peoples' idea of a divine creator is the least objective thing imaginable.