Why is asthenosphere so important to the theory of plate tectonics?

The astenosphere plays a key role in the plate tectonics theory because it is the one that provides the high temperatures, high pressure, and magma, that are the ones responsible for cracking up the crust on the surface.

The astenosphere, with the ability to crack the crust on the surface of the planet is creating the continental and oceanic tectonic plates, and it also provides the push force from bellow so that they can move across the globe and thus be creating the landscape on the planet.