Wouldn't a larger platform over which the whole foot is centered make cycling easier and more efficient?

I haven't found a single example online yet, so before I go ahead and try to make some myself, can anyone either show me where to buy or explain why this wouldn't work? I'm fairly sure it would be much easier to power forward if pressure was exerted over the foot's standing center of gravity point. Moving the crank backwards, there would be less flexion also. I realise at the forward most position, the leg will have to stretch further, but as far as I can see this is the only drawback apart perhaps from the need for a higher and longer frame.