My experience with suburbs is different from yours. I have lived in places where walking is downright dangerous because the architecture is oriented around cars and the drivers are not accustomed to yielding to pedestrians.
Many homes are designed such that the inhabitants rarely use the front door, using only the garage.
That doesn't sound like suburbs I know. The streets are so empty you can safely walk down the middle of them most of the time. People don't, but you could. (kids used to play baseball/basketball in the streets, stopping play when cars come). Of course to get anywhere you need to leave and so it is never far for a major road that is dangerous to be near.
I am sure that you have seen some pedestrian friendly suburbs. So have I. I never said that they are all hostile to pedestrians. Some are designed for people instead of cars. It is rare.
Many homes are designed such that the inhabitants rarely use the front door, using only the garage.