They are producing everything in China. Even the US manufacturers are going to China for the production due to lower production costs. Also, they are giving loans to every country. If you check country-wise bitcoin holdings, China has higher bitcoin holdings. Other things are they can create any virus and control the world population. They can create the medication for that as well. So they can be the next powerful country in the world.
First of all China is a producing countries and many other countries are dependent on China for the purpose of importing useful material so this is the main reason that economy of China is high.
The people of China are creative so whenever hard situations arises there they does not depends on others but work for the development of equipments that are suitable for handling such situations.
There are lots of electronic material which other countries imports from China which increases its economy so its clear that if people of a country are creative and larger import they make then the economy of that country will be increasing.