Unused cars & parking lots take a lot of space in cities.
In my city there is a single city block which has no roads (special vehicle access only) and consists of a bunch of high rise apts buildings with restaurants on the bottom level.
I stumbled on this area by accident and I was blown away, it was like I had walked in to an alternate universe. There were a group of kids playing in what looks like your typical suburb parkland except this is right in the middle of the city which would normally be packed out with cars and concrete. Makes me wish more of the city was like this.