Second, the first steam engine was invented and manufactured by the French physicist Deneys Papan in 1688, with a cylinder and a piston. Watt is the inventor of the improved steam engine. So your question is wrong, you should ask for improvement.
Third, the "steam engine" was not invented because it was unnecessary. Because at that time, the coal used for steelmaking in Britain was mined from deep wells, and the steam engine used for drainage had appeared. Wow, it just improved the equipment. And China's various fuels, such as coal, may have been mined in shallow layers at that time, and there was no need for machines such as steam engines. If the coal mines in China are deep, China can also invent the "steam engine".
On the other hand, China is rich in human resources, and the cost of using human resources is much lower than that of building a machine. China probably invented other mine drainage equipment, but it was definitely not a "steam engine".
In other words, China has taken a different technological road from the West.