> maybe since the start of the Ming dynasty
Why do you choose that date? The following cycle is a well known model of Chinese history and has been true for millennia (I might misremember a detail here or there): 1. civil war -> 2. cohesion and ascendant power -> 3. corruption and declining power -> goto 1
As an interesting tangent: The model above emphasized order as the priority, which means centralized authoritarian power. A recent history published in Hong Kong[0] says that order was really just consolidated power for the Emperor (or Paramount Leader, as they are called now), but for common people the periods of 'disorder' provided more freedom, prosperity, and innovation. As the author says in one interview:
"Since the imposition of imperial absolutism and centralized government in the Qin dynasty, China has not produced the democratic politicians of ancient times, nor the great thinkers like Laozi, Confucius and Mencius. Quite the opposite – totalitarian society has produced many despotic and violent rulers and corrupt officials and brought China into a great dark age." [1]
[0] China History Revisited by Xiao Jiansheng, published by New Century Press of Hong Kong. I read that it was banned in China, but a best-seller in Hong Kong. This first link is the forward, which I recommend:
https://chinahistoryrevisited.blogspot.com/
https://asiancorrespondent.com/2010/01/chat-with-chinese-aut...
[1] https://www.asiasentinel.com/society/revisiting-chinese-hist...