> The thing is, America is very big. For perspective, America is just shy of the square mileage of all of Europe - but America is just one country... and it has half the population of Europe.
Every time Americans use that argument to defend anything that is wrong with the US policy, it looks crazy to people who are looking at the situation from another place around the world.
Neither size nor population are arguments for anything. There are gigantic countries on the planet that do not have America's suburb/car problem. They not only have well-run cities, but they also build fast trains and whatnot. The main trick is in not setting up entire urbanization and infrastructure to maximize profit for real estate, automotive and oil industries by spreading out people to immense areas like in the US. So, in that regard, the people who say that the 'suburban American dream' was a scam, they are right: It can be sustained in a few very rich regions. It is unsustainable for anywhere else. Even in those rich regions it causes many problems ranging from inefficiency to traffic congestion in the cities where the suburbanites have to go to work.
> When I visit mega-cities, I see overt drug usage on the streets, trash everywhere, homeless camps everywhere
Those have nothing to do with the concept of cities but everything to do with the US policies that prevent social services with public spending in order to maximize the tax breaks for the corporations and the rich.
> We don't get to tell each other how to live.
Actually, they do - you are spending their tax money for your inefficient suburb in a much higher rate than your tax money that they are spending for their city. An inefficient system is inefficient, even if those who run that system can afford to run it - like your local prosperous suburb. For the regional infrastructure in your own locale to be affordable by your suburb, a lot of taxpayer money will have to be spent for the society-wide infrastructure. So that the costs of being integrated to the larger infrastructure can even be affordable in your region regardless of its prosperity. From the larger power network to the transportation and communication networks, from production & supply chains to judiciary, police, even defense & military.
There is no small region that can afford the modern local amenities that they have without having a much larger society making those possible through society's aggregated spending regardless of how rich the region is.