Water covers 70 percent of Earth’s surface and one of its many functions is to act like a lubricant for the movement of continental plates.
“Look at our sister planet, Venus,” Wysession said. “It is very hot and dry inside Venus, and Venus has no plate tectonics. All the water probably boiled off, and without water, there are no plates. The system is locked up, like a rusty Tin Man with no oil.”
Yes… yes… the Tin Man was what I immediately thought of after a reference of Venus and lube.
Also, how big of a change is this from the standard “Earth is full of melty shit and metal” view?