Can somebody give me a good argument in favor of objective morality?

[Aegon]

I read something that says a majority (56%) of philosophers identify as moral realists.

From my perspective, morality is almost obviously subjective. Humans decide what is right and what is wrong within their own community. I can't think of a single thing that is moral or immoral today that wasn't the opposite in another time or in another culture across human history. Murder, rape, treatment of women, torture, the list goes on...all were acceptable in certain contexts at some point (and we still didagree today on the morality of a few of these things). Because the society deemed it so. And if we were not here to dictate moral rules , then there would be none at all. No animals are abiding by them, that's for sure. And obviously no religious text can be called objective moral law, because then we can have all sorts of fun pointing out what people in biblical times thought was perfectly fine that is appaling to us today.

A universe that was not created for us, that existed for so long before us, could possibly have within it an objective morality waiting for an advanced species to discover and implement? Seems very wrong. Am.i thinking about it in the wrong way? I'm sure there are arguments in favor that I haven't considered.