Fine, we are talking about the trhee main urban centers of the US here - not the whole country. Now that this strawman is out of the way- are we allowed to continue?
You make a good point about policing. Density wouldn't explain why policing in Tokyo is better and cheaper than in New York.
The rest of the country isn't paying for a thing in NYC - it's the other way around. Just leave us more of our own tax money and we could do all sorts of things that aren't currently considered possible.
At (roughly) what number of people does that argument stop working? 5M? 500K? 50K? 5?