Subsidized in a way that they get a disproportionate amount of services perhaps. But I would argue that is almost irrelevant. Costly services like schooling and transport infrastructure scales mostly by the amount of people.

You could of course calculate business taxes proportionally to the work suburbs deliver, but that would be quite dishonest.

You can always say that only the most densely populated place carries its own... but that isn't convincing. I am not from the US, but we have similar discussions here. That people have to live in the city if they want to live efficient. Problem is that few want to and I think at that point the discussion should be almost ended.