Why does Mercury have more craters than the other planets?

On planets like Venus, Earth, and Mars, we do not see as many craters because most of them have been eroded away by wind, rain, volcanic activity, and other forces. On the giant gas planets, Jupiter, Saturn, Uranus, and Neptune, we do not see any craters because there is no visible solid surface for the meteors to hit. On Mercury, where there is no atmosphere, there is no weather to erode away the craters, so most of the craters are still visible.