I live in a large European metropolitan region with excellent public transport and bicycle infrastructure - at least comparatively. While both leave massive room for improvement a car is not needed, especially as alternatives like car sharing exist for moving heavy stuff once every few months.
There is quite the large support to completely prohibit car use in the inner city aside from transportation, taxis and deliveries. There are hundreds of streets and places where cars have NO value, take a lot of room, blockade other participants in public life and actively worsen the urban environment for everyone. Getting rid of personal cars in these areas would free up massive amounts of space as parking slots can be reutilized and 3-lane roads become single lane.
I love cars and love driving but I hate hate hate them in inner cities. Dense, well-connected urban centers are very suitable to completely outlaw cars whereas suburban or rural areas are absolutely unsuitable to do so.
An improvement doesn't have to be 100% on day 1.