https://www.reuters.com/markets/imf-warning-china-puts-japanization-risk-spotlight-2023-10-13/
Hiroshi Wanatabe, Japan's former top currency diplomat, recalls how Chinese policymakers eagerly studied ways to avert a Japan-style burst of an asset bubble that led to prolonged deflation and economic stagnation - until around 2015.
China has risen way less in terms of GDP per capita, even using power purchasing parity estimates. Japan is at 52k $, China only at 23k (Wikipedia).
I cannot ultimately judge this but the common wisdom about the Chinese social contract seems to be that the citizens get comparatively high economic security for comparatively low civil liberties. And while China's pro-poor growth has certainly been more than impressive historically, I am not sure that the comparatively still low incomes especially in the inner parts of China are sufficient to maintain this social contract if growth does really slow down significantly.
Edit: I agree in general though that the state of Japan is probably not be as bad as it is made out to be in the article.