Smaller cars will continue to kill a few billion animals yearly. They will also continue to kill around a million of humans every year, or about one human every 30 seconds.
The area covered by parking lots is mostly impervious and contributes to flooding as well as heat islands. Cars and parking lots make cities hotter and are worsening climate change. They also contribute to noise pollution. And no, electric cars are not better for noise because at highway speed they are as noisy as fossil fuel cars, and at low speed, their pedestrian warning system is also louder than fossil fuel cars.
I can be nuanced and understand that some people will always need a car, but most people in the world live in a town, a suburb, or a city, and the existence of the vast majority of those cars cannot be justified, whatever their size. Of course smaller cars are desirable. Electric cars are desirable A mix of electric and smaller would be better than status quo. But fewer cars is even more desirable.