There are many wealthy societies that keep growing instead of declining, and many poorer societies that get stuck in a trap and decline. That's the billion-dollar question wrt. China that nobody knows the answer to: will they keep growing and reach a Western-like standard or will they fail to pursue the reforms they would need and get stuck with a middling average income, like so many countries in South America today?

As for the policies that worked there - Deng Xiaoping said "black cat, white cat, if it catches mice it's good cat". But today the popular thing in America is to talk a lot about the ideology of being black or white, and just forget about that catching mice thing.