Bedrockgames
I post in the voice of Christopher Walken
No problems.
To expand my thoughts, I find it somewhat silly to imagine life with supernatural counterfactuals while simultaneously insisting on simulated factuals for things like imagining life in Middle Age feudal societies. IMHO, it's impossible for me to imagine that a world with D&D style magic and ancestries, rather common or not, would result in a social outcome that produced the Middle Age (Western) Europe, its various societies/cultures, and accompanying norms. The mere existence of magic as a form of "capital" would have a tremendous transformative impact on the development and shape of human societies. That most everything else in human society is the same but there is some old guy in a tower who can cast fireball breaks my own sense of "realism" far more than any dramatic contrivance around player characters.
You can take it as far as you like though. Plenty of settings assume magic, assume medieval and run with the conceit that this has no observable impact on the culture, and just do their best to emulate a medieval style world that happens to have D&D style magic in it and monsters. But you can also run campaigns where you seriously think through the implications. It isn't impossible because clearly people do manage to imagine it. No one is saying "this is 100% how it would turn out" or offering it up as some kind of objective scientific experiment. It is merely a thought experiment. There is a whole field of history dedicated to this exercise. It isn't a science, it is more of an art, maybe a craft, but its aim is to help illuminate our understanding of how real history operates. And it isn't taken seriously the way real history is. I still think counter history books are fascinating to read and that it can be an interesting thorough exercise.
Also to be clear I am not saying this is a requirement of 'simulationist' play, just that this kind of thinking is often present and a kind of tool