The earth is round, the equator is wide and the poles are narrow, but when drawing a map, there is no way to draw a paper into a circle, so we can only choose the one with the smallest deviation by projection, which will naturally deviate from reality.
China's land area is 9.6 million square kilometers, and the United States is 9.3264 million square kilometers, with little difference; The map of the United States presents a rectangle, and the map of China looks like a rooster, which visually feels that the rectangle has a larger area. This is a visual problem.
Map of America:
Map of China: