"China is a country that is thousands pf years old, with a population of 1.4 billion. They don't do "existential crises"."

They've had plenty of existential crisis such as: the dissolution of the empire into the Three Kingdoms, the Mongol Invasion, Taiping Rebellion, Sino-Japanese war...

It could easily be argued that the country is going through one right now where the current communist regime is under threat from multiple directions internally. The "nine dash line" policy in the South China Sea and other border disputes may lead to open conflict with the United States, Russia, India,  Australia, NATO and most of Asia.  It also has a debt of US$28 trillion and counting which requires one third of its GDP to service and is larger than the GDP of the United States, Japan and Germany combined.