Here's why:

* Power of Flowing Water: Water, whether in the form of rivers, streams, rain, or ocean waves, has immense erosive power. It can carve out canyons, shape valleys, and transport vast amounts of sediment.

* Chemical Weathering: Water plays a crucial role in chemical weathering, breaking down rocks through processes like dissolution and hydrolysis.

* Glaciers: Though glaciers are technically ice, they are a powerful force of erosion. Their sheer weight and movement carve out valleys, create fjords, and transport massive amounts of rock and sediment.

While other agents of erosion like wind, ice, and gravity play significant roles, water is the most dominant and widespread force shaping the Earth's surface.