to some extent, right, we're demanding more rigor of medievalesque fantasy when we ask "where does the cloth come from" or "how does sewage work" than actual medieval fiction supplies - the closest you'll get to cloth provenance is "it was from 'The Indies'" if you're trying to show how expensive, rare, and/or magical it was, and Lancelot may get locked in a tower for a week or so but he never has to use a chamber pot.
the difference, of course, is that when Chrétien says "a bed had been set up, the sheets of which were by no means soiled, but were white and wide" that is remarkable because his audience knows that laundry, especially laundering to perfect whiteness, is hard and requires resources and time - even if you're trying to write medieval fantasy that's trying to get into the mindset of a medieval person, a modern writer has to do a lot more to signal to the audience that this bed is nice.
but while these material realities certainly shape the mindset of the people living in them, for me the thing that conveys pastness more than describing them in detail is having people act in accordance with them - you can say "Marie had spun and woven this robe" but if Marie then discards it because it was torn or stained, it doesn't matter.
but honestly, more than that, there are a lot of dilemmas that are very compelling to medieval audiences that modern audiences find less so - in le chevalier de la charette, lancelot's greatest fault is that he did accept dishonor for the sake of his lady, but he didn't accept it fast enough. roland waits until the last minute to blow his horn to call charlemange's army back to his aid, and when he at last goes to do so, olivier tells him that it's dishonorable now, when it's clear he's doing it out of fear.
if there's a conclusion here, it's that when a text is described as "feeling medieval" it can mean many different things, and some of them are more immediately accessible to modern audiences than others.
i need a lot of audience buy-in to write a new Arthurian romance with Chrétien de Troyes as a model - the magical elements are rarely explained and are treated in a way that's actually fairly close to a Marquez-like magical realism (Chevalier de la charette: At midnight there descended from the rafters suddenly a lance, as with the intention of pinning the knight through the flanks to the coverlet and the white sheets where he lay), and they often turn on problems that would seem ridiculous to modern audiences.
i need less buy-in to write a story set in a quasi-medieval period where people believe things that people in our middle ages believed, but i do definitely need some - a main character who is genuinely distraught because they saw a raven flying over the road on their way to market might be a hard sell.
and of course it's easiest of all to pay lip service to the idea of realistic medievalism by only putting in the material conditions without the belief system they create.
but we do these things (try to write good medieval fantasy) not because they are easy, but because they are hard - i think it's worth it to try!
