My POV: morality is (largely?) innate, and if I lined up 100 people and we really went full Socratic method we'd see it, with only a few ridiculously disturbed and confused people arguing against whatever we acknowledged. It's just complex, because some things are very case-to-case and people just want moral rulings under 10 words because complexity is scary and they lack discernment (the Germanic "a rule is a rule is a rule and I follow it because I'm a good boy" attitude comes to mind, for instance, which can easily end up in "I was just following orders, I was being a good boy!"), but the vast majority of people are reasonable enough we'd come to an understanding given enough time... in the vacuum of propaganda and brainwashing, ofc.

That's why there's only one true religion.