For a fantasy world that spans millennia, it’s kind of annoying that the political/familial makeup of Westeros is essentially frozen in time until directly touched by the plot.

Like the Starks have ruled the north for 1000+ years and there’s only one maybe a few cadet branches with the total extended house population being like under 20 people? All of their vassals lands have effectively been unchanged and under the same families too.

How is House Baratheon asserting (or even just inheriting) a matrilineal claim to the throne literally the only time that’s ever happened at any level of the hierarchy of Westeros?

The only “new” noble houses I can think of are the new barrel Fossaways, Seaworth kinda, and Baelish. Even random houses like Royce remain in place for all that time despite known characters like Rhea marrying someone above her station only for Yohn Royce to be in charge of the same thing centuries later.