> It turns out that offering urban-level services at suburban density isn't sustainable.What do you mean by "urban-level services"? If you mean urban-style mass transit, then yes, I agree--and I don't want such services in the suburbs. If I'm going to live in the suburbs, I'm going to own a car and that's how I'm going to expect to get around in the suburbs. If I wanted to live in a place where I could walk or use mass transit to get around for all of my daily activities, I'd live in the city, not the suburbs.
> It turns out urban areas are subsidizing suburbs quite extensively.
No, it turns out that politicians and ideologues who think everybody should live a certain way, are trying to impose that way of living in areas where it makes no sense, and using our tax money to do it. That's not a "subsidy", it's just incompetent leadership. Living in the suburbs, I get zero value from all the public expenditure on mass transit in areas which are too low density for it to make sense. So I would be fine with all those expenditures just stopping altogether.
In fact, such expenditures can have negative value to the very people they are supposed to be helping. In one suburb I lived in, I could drive for about 15 minutes to a commuter parking area and catch a bus that took a half hour to get to a stop within walking distance of my workplace. Then the urban planners decided that it would make more sense to spend public money to extend the subway out to that area and outlaw the bus--meaning that from the same commuter parking area, I would now have an hour's trip to the same stop within walking distance of my workplace, during which I would have to change trains, at a higher per-trip cost than the bus was. Which meant it no longer made sense for me to take mass transit to work.
> car-dependent suburbanites demand access to urban areas
What kind of access? I'm fine with using, say, a train to go into the city if I need to do that. Or parking somewhere on the outskirts of the city and using mass transit to get in further.
> non-car-dependent suburbs do seem to work.
Again, I think this depends on what you call a "suburb". To me, if you're living in an area that has a high enough population density to make street-cars, for example, workable, you're living in a city, not a suburb. If I want more space than such a place can provide me, I'm going to live in a less dense area where mass transit is not workable, and as above, I'm going to own a car.