How does usage of cloth bags help environment?

Cloth bags are widely re-useable. If someone did not use cloth bags, say for example, for grocery shopping, their other options would be paper or plastic bags. These are then just thrown into the garbage and end up in land fills and garbage dumps around the world. While paper bags will break down soon enough, they still take up space. And plastic bags can take hundreds of years to fully biodegrade, and the plastics and chemicals can be harmful to the environment. Using cloth bags helps to reduce the waste produced from the other 2.