12000 years ago, Egan landed, and our ancestors had come to Westeros and won the magical war with the son of the forest. But in such a long historical process, Westeros did not develop modern science and technology. According to the historical records in the book, the level of science and technology seems to have stagnated.

A simple answer is indeed the author's will. More complicated, there are many contradictions in the novel.

For example, the aristocrats in Westeros do not like reading, but learn riding, guns and fencing from an early age. Wen Tai also mentioned that it took a long time to teach Jamie to write letters. There are quite a few aristocrats who like reading, such as Sam and Little Devil, and there are customs represented by competition. This represents the militaristic society in Westeros. Most of the nobles have no education, and much of their knowledge is stored by "bachelors", which is very similar to the real clergy class.

Paradoxically, the little devil once said that Westeros civilization was unprecedented. According to the novel, the slave society in the East is more like the pre-Roman society and lags behind them. But in fact, Westeros was only a feudal landlord in the system, and the managers did not form a bureaucratic system. The whole country is maintained by the command meeting of the cabinet, by a set of theocracy and chivalry. The most incredible thing is that such a mainland that values martial arts over literature has a learning city, the largest library and a bachelor's degree, and it is strange that it will spend money to support this place. There is a university with the same ideal address and a bachelor who loves experiments as an undergraduate. In theory, there will be the flame of scientific revolution, but in fact there is no flame.

In addition, the son of the forest at the beginning of the whole Westeros continent was not mentioned. Then the ancestors believed in the ancient tree gods, similar to the Gaul gods believed by the British Celts in the past history, and then the golden Andals invaded, which was completely prehistoric in Britain (Saxon and Anglian aggression).

Generally speaking, the book tends to beautify pre-Western history. In fact, the Middle Ages after Europe and Rome are generally considered as the dark ages. This book itself is also a magical genre, so don't dwell on the development of science and technology.