My classes on medieval (particularly medieval French) history in my last few years at university made watching GoT much harder, as if the show needed any more help with that at the time: this was around season 6. What struck me was how Westeros didn't just lack the institutions, limitations or fundamental worldview to feel authentically medieval as so many others have said in earlier pages, but how it also didn't seem to have anything resembling a medieval social contract that made sense.
The nobility seems to exist to dress nicely (until everyone started adopting the same wardrobe in the last few seasons, anyway) and feast on the tears of their smallfolk, as opposed to doing anything productive outside of rare individual cases like Margaery Tyrell. People like Gregor Clegane are allowed to run rampant over everyone but their bosses and to pointlessly terrorize their subjects when there's no war on. The rot is allowed to escalate all the way up to the top, with apparently nobody other than Tyrion even trying to rein in Joffrey's excesses, and somehow the only popular backlash his sadistic and tyrannical behavior brought on (at least on the show) was a single riot. (Tywin does put him in his place in like two scenes, but didn't make any lasting correction to Joffrey's behavior outside of said scenes)
Meanwhile in reality, medieval lords gave to charity - making oft-quite generous bequests to hospitals, leper colonies and such, donating food, or more rarely personally working to try to alleviate their suffering in the vein of Saint Elizabeth of Hungary - all the time. Genuinely murderously insane kings like Charles VI were marginalized in favor of a regent/regents or disposed of in favor of heirs that people around them could actually work with. And Gilles de Rais' crimes got him hanged & burned more than a decade before the Hundred Years' War ended, despite him being a prominent French commander who had partaken in several major victories
and a personal companion of Joan of Arc.
I would go as far as to say that Martin's portrayal of the Westerosi nobility has more in common with how QAnon people see the modern elite than it does with how any medieval European aristocracy conducted itself: that's to say, they're an entirely parasitic class of cackling evildoers who contribute nothing to society, command absolute power over their subjects in blatantly corrupt and incompetent ways and who commit whatever evils they want, no matter how illogical and counterproductive, but somehow still manage to get by without facing any serious challenges from above or below - as opposed to the real social upper class of the Middle Ages, which was comprised of people who behaved like people and actually had quite a few social constraints, conventions, duties and expectations weighing them down.
Not to mention how Edmure letting the peasants shelter inside Riverrun is portrayed as a great aberration when half the point of castles was as shelters for peasantry in time of war.
Another excellent example. Under the social contract which bound real medieval societies, the role of the nobility - 'those who fight' - was not just to rule but to defend their subjects in times of conflict. The French nobility not doing this during the Hundred Years' War, or at best not doing it very well, sparked
La Jacquerie which threatened to upend the social order and (in conjunction with the Parisian bourgeoisie) briefly locked the French royals out of their own capital.
It made sense as to why nobody rose up while the Targaryens had dragons, but afterwards? The insane contempt for peasant lives displayed by what feels like 99% of the Westerosi royalty and nobility, to the point where Edmure is considered practically a living saint (or an idiot by his uncle and nephew, both of whom are supposed to be great military commanders...) just for carrying out the most basic responsibilities expected of a noble lord, should have resulted in either their overthrow or massive concessions to appease the commons. Especially considering their society's been around for 10,000 years and the last two dynasties have spanned 300 years, a little more than half of which was spent without dragons around.
