When you step back you can see that suburbs have existed since 1880 (street car suburbs), and most of them are still around. The roads have been replaced several times since then in most - they don't last for 140 years so they must have been. Likely the first ones didn't even have water/sewage pipes, but they all have that now so somehow they added them. We know how long pipes in the ground last (both average and maximum), so we know they must have replaced at least some of them at some point since they were added. We know that telephone and electric would have been built sometimes between 1920 and 1950 - and we know those wires don't last forever so they got replaced. We know that cable TV was added likely between 1970 and 2000, some of those much be wearing out and been replaced. We know that fiber is being added now.
I don't know how they managed to do the above. However we know that they have done it, and the costs must have not been excessive.
When you show me facts I'll change my mind. Until then the above facts are compelling.
Sure. But you are assuming that somehow all those expenses come strictly from those same suburbs. Or if there is the is an external inflow (also known as debt) it is not larger than for the similar population low rise blocks. And I say that is far from fact, even without giving my own opinion.
Basically you are making correct observations but only for part of the picture. And if the discussion is about finances and economics, I would say that the part about where money comes from is pretty damn important, no? :)
Also, even from across the pond, I also saw historical photos of the old USA. Those suburbs from before WW2 were way closer to the Europe really. There were more small businesses everywhere, there were commerce blocks etc. And pre-WW2 infrastructure was much cheaper and less complex that contemporary one. So sure, old suburbs were probably much healthier economically.
As for the moderns suburbs (from 50s and up) you can view more knowledgeable people than me if you really wish to uncover facts and truth. I won't post spoilers, but you may guess them from the context easily.
I don't know how they managed to do the above. However we know that they have done it, and the costs must have not been excessive.
When you show me facts I'll change my mind. Until then the above facts are compelling.