Cars are rapidly going electric, silent, and intelligent. The first two improvements will remove the problems with pollution and noise. The idea that the production of an electric car produces a vast amount of waste and pollution is nonsense, big oil propaganda.
The added intelligence will provide benefits further down the road, some of which we don't even know yet. Once cars are smart it promises to radically improve safety, with smart cars able to avoid most accidents, drive drunk people home in the back seat, able to drop the owner at their office door and then find somewhere to park on their own, either in a more spaced-out area or an automated dense public garage.
Removing some roads and replacing with more shared/human-centric transport will make a huge difference to the utility of cities. We can do this independently of electrifying vehicles - see superblocks [1]