SUVs are still popular and large trucks are just awful. It's a big problem in this country. But most of the cars sold aren't actual SUVs. They're CUVs. They're built on car chassis. They are heavier, which means they get worse fuel economy than their car equivalent. And they're less aerodynamic, which means they get less fuel economy than their car equivalent. And that weight means they also erode their tires faster, which of course is just worse for the environment as well as well as their brakes and other components.

That said, the difference in size compared to their sedan equivalent, or even hatchback, five-door equivalent, is not tremendous. Even efficiency, the loss is usually maybe like a couple of miles per gallon on the tests. Though I imagine if you try to hyper mile and you know baby is a throttle you can get more out of the car-shaped vehicle than you can the fake SUV/CUV shaped vehicle.

i think this is about toxic gases emissions vs CO2 emissions. while CO2 emissions have probably gone up somewhat (my guesstimate is +30% since 1970), the toxic gas emissions have almost completely gone to zero. there was a whole lot more toxic gases around in the 20th century industry and machinery, you had to cough constantly, we just don't remember it because it's comparatively clean now.