Why are we still using cars instead of hovercrafts?
Hovercrafts are not more efficient than wheeled vehicles. It is like comparing apples to oranges. Each has advantages and disadvantages. Yes the hovercraft is amphibious, but since it is riding above the surface on air, there are no brakes and you are subjected to winds just like an airplane!. That means if you are flying down the road in a crosswind, you have to fly sideways to stay on the road. Also, all roads have a “crown’ on them for rain runoff. The hovercraft will naturally seek the lower point; so you are always sliding off the side of the road. How do I know these things? Because I have been making and piloting (small) hovercrafts for over 30 years, and the last time I took one down a road, I took 3 mailboxes with me! Hovercrafts ARE awesome, but they will not replace the wheeled vehicle.