small cars are not popular, and large cars have much more aerodynamic drag and therefore require bigger batteries. Bigger batteries dramatically increase the cost of the car.
The fact remains, in the US market small cars are not popular. Its not a conspiracy of US manufacturers "lagging deliberately". There of course is more margin to be made on bigger vehicles but its a mixture of both consumer demand and margin incentives.
small cars are not popular, and large cars have much more aerodynamic drag and therefore require bigger batteries. Bigger batteries dramatically increase the cost of the car.