Yes I do, but I entirely disagree that it’s a history of “stagnation.” Indeed, this is one of my pet peeves about the ASOIAF fandom – Westeros is not stagnant either technologically (moving from the Stone Age to the Late Middle Ages), culturally (the arrival of the First Men, their assimilation with CotF culture, the arrival of the Andals, the assimilation of most First Men into Andal culture, the “Old God and the New” tolerance, the arrival and integration of the Rhoynar into Dorne, etc.), or politically (the shift from a hundred kingdoms to Seven, then from Seven to the Iron Throne, then from Targaryen hegemony to the Baratheon dynasty to civil war).
Moreover, WOIAF actually supports a narrative of technological change over time:
…in the first age of the world, the Dawn Age, men were not lettered. We can be certain that the world was far more primitive, however—a barbarous place of tribes living directly from the land with no knowledge of the working of metal or the taming of beasts…
…The children of the forest …worked no metal, but they had great art in working obsidian…They wove no cloths but were skilled in making garments of leaves and bark…they made their homes simply, constructing no holdfasts or castles or cities…
…unlike the children, the First Men farmed the land and raised up ringforts and villages. And in so doing, they took to chopping down the weirwood trees, including those with carved faces, and for this, the children attacked them, leading to hundreds of years of war. The First Men—who had brought with them strange gods, horses, cattle, and weapons of bronze—were also larger and stronger than the children, and so they were a significant threat…
…the Valyrians hungered for…copper and tin for the bronze of their weapons and monuments; later iron for the steel fo their legendary blades; and always gold ans silver to pay for it all…
…the Rhoynar…were said to be the first to learn the art of iron making…
…the Andals brought iron weapons with them and suits of iron plates…The fact that the Andals forged iron has been taken by some as proof that the Seven guided them—that the Smith himself taught them this art—and so do the holy texts teach. But the Rhoynar were already an advanced civilization at this time, and they too knew of iron, so it takes only the study of a map to realize that the earliest Andals must have had contact with the Rhoynar…and it would not be the first time that men learned of the working of iron from the Rhoynar; it is said that the Valyrians learned the art from them as well, although the Valyrians eventually surpassed them…
…Sweeping through the Vale with fire and sword, the Andals began their conquest of Westeros. Their iron weapons and armor surpassed the bronze with which the First Men still fought, and many First Men perished in this war…
…The Rhoynar brought considerable wealth with them; their artisans, metalworkers, and stonemasons brought skills far in advance of those achieved by their Westerosi counterparts, and their armorers were soon producing swords and spears and suits of scale and plate no Westerosi smith could hope to match. Even more crucially, it is said the Rhoynish water witches knew secret spells that made dry streams flow again and deserts bloom…
…Tyrosh…not long after the city’s founding, however, a unique variety of sea snail was discovered in the waters off the bleak, stony island where the fortress stood. These snails secreted a substance that, when properly treated, yielded a deep dark reddish dye that soon became wildly fashionable amongst the nobility of Valyria. As the snails were found nowhere else, merchants came to Tyrosh by the thousands, and the outpost grew into a major city in the space of a generation. Tyroshi dyers soon learned to produce scarlet, crimson, and deep indigo dyes as well by varying the diet of the snails…
…The artisans of Myr, many of slave birth, are also greatly renowned; Myrish lace and Myrish tapestries are said to be worth their weight in gold and spice, and Myrish lenses have no equal in all the world…
…The oldest of these—a long-abandoned tower, round and squat and covered with gargoyles—has become known as the First Keep. Some take this to mean that it was built by the First Men, but Maester Kennet has definitively proved that it could not have existed before the arrival of the Andals since the First Men and the early Andals raised square towers and keeps. Round towers came sometime later…
…after Qhored, a slow decline began. The kings who followed QHored played a part in that, yet the men of the green lands were likewise growing stronger. The First Men were building longships of their own, their towns defended by stone walls in place of wooden palisades and spiked ditches…The arrival of the Andals in the Seven Kingdoms only hastened the decline of the Iron Islands, for unlike the First Men who had gone before, the Andals were fearless seamen, with longships of their own as swift and seaworthy as any that the ironborn could build. As the Andals flooded into the riverlands, the westerlands, and the Reach, new villages sprang up along the coasts, walled towns and stout stone-and-timber castles rose over every cove and harbor, and great lords and petty kings alike began to build warships to defend their shores and shipping…
…Braavos has a wall of ships such as no other city in the world possesses…the true wonder is the Arsenal. There, one of the purple-hulled war galleys of Braavos can be built in a day. All the vessels are constructed following the same design, so that all the many parts can be prepared in advance, and skilled shipbuilders work upon different sections of the vessel simultaneously to hasten the labor. To organize such a feat of engineering is unprecedented; one need only look at the raucous, confused construction in the shipyards of Oldtown to see the truth of this…
And so on and so forth.
Indeed, I would argue that if there is inaccuracy in the historical record, it actually is the appearance of stagnation, due to later chroniclers reinterpreting the history of eras thousands of years ago to fit the social order of their own time. As the WOIAF notes:
And besides the legendary kings and the hundreds of kingdoms from which the Seven Kingdoms were born, stories of such as Symeon Star-Eyes, Serwyn of the Mirror Shield, and other heroes have become fodder for septons and singers alike. Did such heroes once exist? It may be so. But when the singers number Serwyn of the Mirror Shield as one of the Kingsguard—an institution that was only formed during the reign of Aegon the Conqueror—we can see why it is that few of these tales can ever be trusted. The septons who first wrote them down took what details suited them and added others, and the singers changed them—sometimes beyond all recognition—for the sake of a warm place in some lord’s hall. In such a way does some long-dead First Man become a knight who follows the Seven and guards the Targaryen kings thousands of years after he lived (if he ever did). The legion of boys and youths made ignorant of the past history of Westeros by these foolish tales cannot be numbered.
It is best to remember that when we speak of these legendary founders of realms, we speak merely of some early domains—generally centered on a high seat, such as Casterly Rock or Winterfell—that in time incorporated more and more land and power into their grasp. If Garth Greenhand ever ruled what he claimed was the Kingdom of the Reach, it is doubtful its writ was anything more than notional beyond a fortnight’s ride from his halls. But from such petty domains arose the mightier kingdoms that came to dominate Westeros in the millennia to come.
So has Westeros been in medieval stasis for eight thousand years? No. Westeros was in the Bronze Age until 6000 years ago, with the ancient Kings of the First Men having far more in common with Agamemnon or Hammurabi than they would with Edward III. If the account of the Rhoynar bringing steel into Westeros is accurate, then Westeros has only had steel for a thousand years and in that time has already hit the Late Middle Ages.
Consider by contrast that the European Iron Age lasted ~1,800 years, and the Middle Ages another 1,000 years.