Imperialism's invasion of China cannot be said to be completely useless. For example, the Opium War awakened some intellectuals in China and accelerated the demise of feudalism.

The imperialist powers invaded China, which objectively created certain conditions for the development of capitalism in China and promoted the development of capitalism in China to some extent. But this is completely different from the "active invasion of China" advocated by western colonialists. The purpose of the imperialist powers' invasion of China is by no means to help China develop capitalism, but its stimulating effect on China's capitalist development is objective. As Marx said, they just act as unconscious tools of history.