One difference - cat corpses in the street probably make pretty good rat food.
Although, now that I think about it, the elevated risk of hitting cats in the street would probably make most drivers slow down in the city, which is aligned with my worldview.
Also, cute cats everywhere. I could pet them. It could be a form of utopia. Sorry birds. Although birds would probably do fine actually, they're extremely well adapted to take advantage of verticality in the city.
I'm in! Ship the cats from the kill shelters to New York so that I may pet all of them!
