Because China’s only apply to Chinese vehicles while the US’s apply to everyone in the industry including foreign brands. This increases competition. China’s goal is to reduce competition by putting competitors out of business so that they can recoup their investment by jacking up the prices once there is nobody left to stand in their way.
That’s a hilarious take as they’re the largest polluter in the world and have terrible environmental regulations. They’re doing it to capture and control the market. How does dumping a bunch of cheap, disposable cars that they’ve shipped halfway across the world after building reduce pollution exactly?
https://www.bloomberg.com/features/2023-china-ev-graveyards/