This is what is happening. Ultimately, very ultimately, the prospects, possibilities, and profits of commerce react back upon the sort of elite which will dominate society politically, culturally, and militarily, as well of course as economically. Does society come to be morally and mentally dominated by pedigreed bluebloods, thuggish warlords, or refined gentlemen who have studied all sorts of irrelevant matter for years in order to become the sort of scholars entitled to become magistrates. Even testosterone explains a little bit, for example. Empress Wu had a more sensible foreign policy than did Taizong or Xuanzong, before and after.
Personality explains a little bit.
But it still takes imagination, which must often be dead wrong, to get beyond such things. Then recall the Princess An Lo, calmly sitting before her mirror in Chang'an, painting the huge mothwing-shaped eyebrows which were the fashion in the early eighth century, until she was beheaded. When your time is up, get killed with style and grace, without making any trouble. Which is deemed to have excused all manner of featherbrained living before that. And if the privileged class does not have privileges, what's the sense of having a privileged class.