Quen are totally dependent on their outdated focuses to the point of not being innovative. It’s given them an advantage for a while, but they don’t understand how they work, and couldn’t easily replace or repair them. Then all of their people live in an oppressive regime where summary execution is common, and theocracy dictates their culture. That stymies curiosity and impedes other intellectual pursuits. The fear and rigidity makes them more subject to destabilizing forces, be they internal and external. The probability that they will suffer imminent collapse is high, especially if a heretical Living Ancestor and her Diviner disciple upset the status quo in the future.
Meanwhile, the Oseram are already experiencing a major cultural shift. Women are tired of being oppressed, and some are leaving, which will eventually become a major problem. This won’t be as destabilizing as the autocratic government with the Quen, though, as the Oseram are ruled by a weak confederacy of clans. They can choose to replace their aging elected Ealdormen and the speed of this advancement will come as more and more cross-cultural exchanges occur, as the Oseram are shown to be the only tribe to travel widely. Once this period ends, the Oseram are also the only tribe shown to invent things outright, which makes them well poised to become the most advanced civilization by their own right. They will undoubtedly be the first to not only harness Old Ones technology through experimentation. Meanwhile, the Quen will probably stagnate or completely collapse. So why would the Carja still be Number One when I spend an entire paragraph on the Oseram?