Speaking of "D&D doesn't actually have a medieval paradigm," I think one of the most fun things done to D&D on various OSR-adjacent blogs has been making an effort to introduce more actual medievalism into D&D, because as said in actual old-school D&D the medieval elements are more of a thin coat of paint. Like, sure, sometimes it's fun to play the medieval fantasy theme park dungeon game, but actually introducing medieval politics and social dynamics into the game? That's fun.
It doesn't even need to alter the gameplay focus of the game: the party will still be largely a group of morally dubious violent problem-solvers who largely engage in killing things who live in holes in the ground and looting riches, but there is now an extra layer of having to think of fiefdoms and shit. The example that stuck with me was a blog post that was like "the dungeon is within land contested between two lords and the player characters are hired to loot its riches by the other lord so as to give them plausible deniability."
One "issue" is that the actual medieval period and the philosophies that were prevalent at that time were very heavily informed by Christianity to the point where my friend @sirobvious has said (paraphrasing, and do correct me if I am misremembering or overtly simplifying your point) that you can't really have a meaningfully "medieval" game without Christianity. I say that this is an issue in quotations because you can just set your game in medieval Europe but now there's elves there. And like original D&D literally just had crosses on the equipment list, they weren't even called holy symbols.
