why are we still using cars instead of hovercrafts?

hovercraft are in existence being used by the military and for recreation. they are cheaper to build and buy, can be designed for one person or large as a bus. uses less gasoline than an automobile. no worry of potholes or hydroplaning or hitting small animals. you wont need to buy a car and a boat when a hovercraft will go straight from the street to the water. we are in the space age and still tethered to wheeled vehicles. let’s fly!
hovercraft and speed laws can be modified. i’ve seen the military craft flying down the gulf over 70mph.