Aerodynamics as well, new cars and especially ev/hybrids are slippery compared to many/the average if we take old cars to mean 50’s through 70’s.
An older sedan-style car might still be more aerodynamic than a modern SUV, simply because the frontal surface area is smaller. The less air you have to push out of the way in the first place, the better.
Does that matter much if you only drive around town at 30mph?