Count up the glorified open air malls in your area and do a little local history.
This can be casually done by noting average home build dates in various neighborhoods. Find a neighborhood with houses from the 40s/50s and note the layout. Then find a neighborhood built in the 70s and note the layout. You can do that with any number of real-estate tools and/or Google Maps.
Just in the county I grew up in there was at least a dozen of those small towns -- each with shops, mainstreets, mixed-use zoning, surrounding homes, often with train stations and/or bus depots (some surviving to this day), all very walkable and livable.
Then the farmland around them was cut up into suburbs in the 40s and 50s.
But even those were notably different from modern suburbs: walkable, smaller lots, still some mixed use with corner stores and restaurants. The cul-de-sac and single-use zoning atrocities didn't start showing up until the 70s, when they basically stitched the old towns and old neighborhoods together into one largely-unbroken stream of Modern Americana.
And again, the thrust isn't that we should all have small towns or that suburbs are wrong for everyone. It's that the old spectrum has been reduced to a binary.
You have suburbs and you have New York City.
The fact that 'US city' discussions always revert to talking about a handful of the oldest cities is itself a tell: if it didn't grow into a city before suburbanization, they didn't really grow into a city. Many look for all the world like a high-rise downtown bolted onto suburban sprawl like an upscale version of a big box strip mall. They don't really "count" as a city like New York or Chicago and we all know it.