> more traffic - more noise - more pollution

These are often true, but not inherently so. I've lived in remote rural, suburban, and dense city environments. My dense city had disadvantages, but it was quiet and had little traffic or pollution. In my experience the suburban environment is the worst for all three once you get off the residential streets, there's loud, polluting traffic (3/3).

In two of the places I lived, I couldn't keep the window open due to the constant tire noise. It wasn't an issue in the densest place I lived, which was a low-car-traffic place and pleasant to be outside in. Now, I live right next to a freight rail yard, but I don't find the train noise grating like the highway noise.