I’m not disrespecting what Cambodia has achieved, but its not that special
They started from an extremely low, even primitive level. The country was at war for decades, then faced an absolutely extreme, insane Communism for several years. Then they were invaded by Vietnam.
Cambodia is still in no way ruled by wise, enlightened, incorruptible libertarians. In fact, quite the opposite. But remove those previous extremes, and any society will start to find its back to normal in a relatively short time.
They, sadly to say, were at the top of their game while occupied by the french.