The US has a highly developed economy based on services. Medical and education is a significant part of it, but you don't have to be in the US for long to appreciate how diverse the economy really is. There are a million ways to spend money in America and that's all counted in GDP. China for political reasons is unlikely to ever have an economy as diverse as the American economy. Even politics itself in America is a large chunk of GDP when you think of all the spending at local, state and national levels for political campaigning, advertising and lobbying. Think of the sports sector which is practically nonexistent in China compared to the US, where there's everything under the sun and a new sport is created every year. Think about things that are outright illegal in China like pornography and marijuana or crytomining. All of these things go into the GDP number.
China is also culturally not nearly as much oriented towards consumption as the United States. But consumption is what GDP measures. "Dual Circulation" shows that they know they have to boost consumption but it won't be easy. They have to get people to take up hobbies, watch sports, join a gym, go clubbing and all of these other millions of things that people do and spend money on in the West.
