It certainly helps the cause Peter, but it's not the be all and end all.
Usability, tractability, power delivery, power to weight ratio, handling, grip, aerodynamics. Everything matters.
Of course different cars are better suited to different roads too! A fast car on a motorway doesn't always make a good car on a B road. And a good car on a B road might run out of gears/puff on a motorway.