Your theory about "suburbs are supported by cities" is controversial. I already know the video you shared and it isn't very convincing. But arguing about this will basically be the usual link exchange (I'm not an urban planner or state accountant and I assume you aren't either). I have some data for you though:
- My county doesn't have any medium-sized or big cities, so all the county maintained roads (most of our roads) are fully paid by our property taxes, which are relatively low percentwise but, as a high-income county, adds up to a pretty penny. I do most of my driving inside my county.
- A lot of road maintenance comes from the gas tax, which I pay plenty and is used inside and outside the county.
- As a tech worker, my state income tax bill is WELL above the median (like 3x-5x+). And the same applies to the suburban county I live in - these suburbanites pay a TON in state income tax. The county only receives a small fraction of the state taxes, which also goes to subsidize - guess what - city living programs.
- My federal tax bill is also huge, well above the median, as is the case with my fellow suburbanites, so I think I'm paying for all my use of federally funded highways in my state and the next 3 or 4 states to the north (if not more).
Suffice to say, I do pay a lot for this benefit, and I'd pay even more if it came to that. And if it was that much more expensive, land in the suburbs would be a lot cheaper than it is now, which would even the math.