Considering China to be a homogeneous entity in any dimension is borne of ignorance. Linguistically, the four largest cities in China (Guangzhou, Shanghai, Chongqing, Beijing) speak "dialects" that range from barely mutually intelligible to not at all. Politically, the region has had a long history of provinces disregarding central rule, rivalry between major power centers, etc. Cultural boundaries have been somewhat muddied in the modern era, but one should not assume that the united front that the CCP presents to the outside world is reflective of internal unity.
Sure, the Han make up 90%+ of the population (and in that sense you could call China homogeneous), but I struggle to say that Han == Han when it comes to the overwhelming diversity of the country.
The only meaningful distinction is between mainland Chinese vs Hong Kongers/Taiwanese/Chinese Diaspora. There's no ignoring the damage done by the Cultural Revolution. The old honor code that used to govern social relations just isn't there anymore. Mainland China is a complete wild west where anything goes. Cheating. Stealing. Stabbing friends in the back.
Sure, the Han make up 90%+ of the population (and in that sense you could call China homogeneous), but I struggle to say that Han == Han when it comes to the overwhelming diversity of the country.