Biden is only in the pocket of parts of China. There is no monolithic unified "China", despite the image they so desperately project. All Chinese may look the same to foreigners, but the reality is that China has always been a huge mess of different ethnicities, cultures, regions, and local syndicates constantly engaged in low-key warring against each other. This is why its central government always ends up ruling as repressively as it can get away with, why the great majority of Taiwanese islanders still want to remain independant from mainland China, and why there is a deep-seated unspoken agreement among the different mainland Chinese cultures to maintain the image of a singular unified country no matter how superficial it may actually be. The reality of "one China" is very, very precarious, and the moment the facade can no longer be maintained is the moment all of the numerous bickering internal factions end up sending the mainland into a new warring states era.