The "suburbs were never viable" claim is built upon a few facts about most US suburbs: 1) They are advertised partially based on the low property taxes in their

The "suburbs were never viable" claim is built upon a few facts about most US suburbs: 1) They are advertised partially based on the low property taxes in their municipalities. 2) They have restrictive building codes that prevent additional development from occurring. In other words, they are built all at once, to a finished state. Then you run the math on property taxes vs. maintenance costs. If repairing the road, pipes, etc to one additional house costs more money than that house contributes via property tax (over a period of 25 years or so), then the suburb is considered insolvent. It could raise property taxes, or allow additional development, but without those actions the suburb remains insolvent.