In the case of China, the workers and peasants established political supremacy through a long civil war and revolution, solidifying a socialist state in 1949. Capitalists exist in China, but they do not form a coherent political body, the revolution decided that they will not be allowed to usurp the power of the workers.

The issue is your view is clouded with a history, and propaganda. The US decided it wouldn't allow tyrants to take power. Does that actually mean it won't, or hasn't, happened? Of course not. The peasants do not have the same power as the owner class in China. You know that. Why do you insist that they do?

Regarding communism, you're confusing the eradication of class society with the eradication of all centralized administration, and confusing the socialist stage with the classless and stateless communist stage. China has capitalists, correct, because China is a developing country. Communism is not a moral decree, but a mode of production predicated on immensely developed productive forces. China does not yet have those productive forces necessary for the complete eradication of class.

At what point will it? When do you think they'll decide they have the productive forces necessary and dissolve their own power? They're one of, if not the, largest productive force the world has ever seen. If not now, it's never. Those with power will never want to give it up, and they'll do everything they can to cement their power. They'll have you believe they're not, and they're just working in your best interest, and then it'll be almost impossible to remove them. This is how it always goes. This is not a criticism of China. It's a criticism of hierarchy. Those at the top never want to stop being at the top.