This is almost an "arms race" situation, since when there are so many gigantic SUVs and pickup trucks on the road, driving in a smaller car becomes a lot less safe in case of an accidental collision with a larger, heavier vehicle, and the only way to reduce that risk is to drive a gigantic SUV/pickup truck yourself and further exacerbate the problem.

Having this many large vehicles on the street makes driving on the highway dangerous and unpleasant. LA's traffic is especially terrible.