Whenever I try to explain to people why I like GoT I say it's because it's based on and inspired by the social structure of late medieval Europe, of which I am a descendant of. It's kind of like learning about your past. It's this sociological framework that provides the 'meat' for the interactions between the characters.
It goes even further than though!
Western civilization has always made it their mythology that they have a disdain for eastern style despotism. This stretches back all the way to classical times. Dany's returning to Westeros is kind of this fear made manifest - eastern style despotism descending on western freedom. You even have some of the 'noble savage' stuff mixed in there as well with the freefolk and the Dothraki.
All this sociological stuff got tossed out the window when D&D had to rely on their own wits.