Fiction is fiction. The story told in a work of fiction isn't true in terms of it having actually happened, but that doesn't mean that it can't tell or explicate the truth, or a truth. Fiction often does precisely that, though it also may not. ... That doesn't make nonfiction generally better or worse than fiction, though.
Because planets more massive than Earth would retain significantly more internal heat from their initial formation, and because heat drives plate tectonics via the conveyor belt of sinking and rising rock within the mantle, plate activity should be prolonged on such planets.
