Your new car likely weighs much more? The modern market demands a driving experience that's like sitting in our home - complete with huge sofa like seats, air conditioning, touch screen TVs, cameras and thousands of sensors. They can either cater to that or go out of business.
Carting around two tons of unnecessary random tech toys and the kitchen sink is inefficient regardless of the energy source. That's a separate problem.
So instead of realizing gains in efficiency, cars were simultaneously made less efficient to realize gains in safety and comfort. The end result is still cars that are about the same as what they were decades ago.
Carting around two tons of unnecessary random tech toys and the kitchen sink is inefficient regardless of the energy source. That's a separate problem.