You're mixing up suburbs with small towns. If it is within driving range of a big city downtown then even if it is its own municipality, it is part of the greater metropolitan area of the big city.
Suburbs became a thing after the car industry worked very hard to make sure subways and train cars can't be used. And this was also after the great interstate highway project and explicit city planning meant to mitigate the fallout of a nuclear attack by having a huge urban sprawl. All of this in the 50s and 60s.
What outsiders don't see is the massive scope and efficiency of the US interstate highway system which is the artery of the US economy. Discussions about public transport don't consider freight. You can't have freight trains to every big store and warehouse but you can get 18wheelers from any part of america to any other part of america (continental) within a day or two at most.
At the same time, explicit effort was made to make cities difficult to drive or bike in. A lot of this again goes back to the sentiment of the 50-60s where "white flight" was still a big deal and making suburbs inaccessible to certain types of people who live in cities but occupy the lowest social classes was also important.
It's expensive to be poor but cars means mandatory insurance and car payments, gas, repair bills and parking fees. And if you manage to overcome all that, cops can pull you over and search you without a warrant because you are driving and of course traffic fees and all that is nothing compared to one's safety. Childcare, food or rent? Which one should you sacrifice for that court fee? And somehow you must maintain mental fortitude to not use drugs or alcohol to cope with all that stress. Take out cars and suddenly so many problems are solved (including crime rates).
My point is, much of this is by design decisions made at a different time and era and the hostility is intentional. It is possible to have both a walkable and drivable city with much less parking lots, especially by having less single family housing concentrations (condos instead of large communities of houses that require cars to access).