I agree with you in this case that the problem is complex
(I think I actually probably agree with you more often than it may seem on that, I probably come across as thinking things are simple if what I actually mean is that I've thought about them long enough that I have a position or solution I'm keen to argue for!)
I think communicating what is at stake always takes time, though there are possible strategies to do it: you need to have a foot in multiple worlds, though - that is, the readers probably need to be on board with "I want the best/worst for this character" before you can get into "and in this society, the best/worst for this character may require X, here's why". That makes it hard to simulate every aspect of a past culture
at the same time, because if people don't have the mental hook (or prior experience of the setting) then you don't give them a way in. This is one of the reasons it takes time, because you probably need to get particular ideas into a reader's head more or less one at a time, and some of them interlock so you need to ease them in next to one another or sitting awkwardly or something.
And even historians and anthropologists often aren't good at having the full sweep you need for a book or a game: I think I could write pretty convincingly about elite Caucasus nobles in a court context, but I might struggle to capture the same people's attitudes to faith in nearly the same depth because I don't have the same depth of knowledge of the hagiographies and sermons of the period, or indeed of medieval Orthodox religious practice and experience more widely, as I do in the chronicles and secular texts that are my primary specialism. So if I wrote a fictional text about a young nobleman and his romances in the Georgian court, I might be able to get across to readers certain ideas about the relationship between women and power, and the ways in which a
dchabuki should act, but I'd plausibly end up understating the religious aspects and experiences of his life and how those affected his view of interpersonal relationships. I worry about this which is one of the reasons I haven't tried writing specifically historical fiction about my period of study.
Also such a character can often only show what the mores of the culture are by testing and pushing against them, though I think that's generally a difference between fiction and reality: characters even in fictions in the premodern period do a
lot of telling us what society thinks you should do by doing exactly the opposite and facing obstacles or punishment for it.