People only need cars because people have cars and cars make cities worse for everyone outside of one. If nobody owned cars everyone would get by just fine. It's a race to the bottom.
I my self live close to the good American cities and even though my community is rather rural (I literally live across the street from a dairy farm) I still prefer biking to town. And when I go to the city, I rarely bring my car with me, as I prefer the bus over waiting in the ferry line and dealing with parking in the city.