History

I can't remember who was talking and speculating about this, but China had been through a number of centralizing than fracturing periods then centralizing again and repeat ("the Empire long united, must divide. Long divided, must unite") for whatever reason.

When periods of unification happened, an outside force or theory of government would come and unite all of China (whatever "all" meant for that period). The Yuan dynasty from Mongolia, the Han dynasty bringing about confuscianisn on a grand governmental scale, etc. And when it came time for to divide after disunity and corruption of the Qing in the mid 19th century, it probably would've been under the Heavenly Kingdom syncretized Christianity - except for the intervention of now world bestriding imperial European great powers, which had a vested interest in maintaining the Qing and later the Republic.

In the end, it was still an outside force that put an end to banditry, disunity, etc. Or another fracturing period. It was marxism and Maoism, and it was the establishment of the PRC (notwithstanding the ROC in Taiwan).