Sure, but only if your world begins and ends with the urban public transit map and only includes white collar workers. Outside of areas with good public transit cars are the next best thing, and those areas start much closer to urban cores than you want to admit and even within good transit areas there is a huge amount of economic activity where the point to point nature or cargo capacity of cars enables economic activity that is not otherwise economically in the black. We need to have some amount of car infrastructure to enable all that. A side effect of this is that a bunch of urban workers who don't really have a good argument for commuting by car can and do because they can afford the luxury.

It depends what you mean by efficient. A bus is more energy-efficient but a car is way more time-efficient.