Why don’t clouds (on Earth or Venus) fall on the surface of planets?

Water droplets or ice floes in a cloud are acted upon by gravity and buoyancy (Archimedes’ force). Compensation of these two forces in air is impossible, and therefore the droplet moves downward. In this case, there is a resistance force of the medium directed upward. With steady motion, the droplet falling speed is low. In the lower warm layers of the atmosphere, a small drop evaporates, and large drops fall on the Earth in the form of rain. In the case of convective air movements, the cloud can exist in the atmosphere for a long time.