Here's why:

* Water is a powerful solvent: It can dissolve rocks and soil, carrying away the particles.

* Water is a powerful force: Rain, rivers, and waves can erode landscapes by carving out valleys, canyons, and coastlines.

* Water is abundant: It covers over 70% of the Earth's surface, providing ample opportunity for erosion.

While other factors like wind, ice, and gravity contribute to erosion, water's role is far more significant in shaping the Earth's surface.