Clearly education and other factors influence economic outcomes.
All other things being equal, demographics have a powerful independent effect on the economy.
The most economically stimulating element of the population are young adults, just starting out (that years graduating class). They need everything to furnish their households, will be raising expensive families, and have the energy to work long hours and second jobs. There had been a growing graduating class in China every year during the boom.
Additionally, China’s migration from the farms to the cities was the largest in human history - very stimulative.
Both of those powerful trends have peaked, and are now on a slowing trajectory.
The one child policy is an extreme intervention, whose effects are now pronounced in the age and gender distribution of China - it will take a generation to normalize, if allowed to do so.
China is a fake house of cards ready to fall apart.