Definitely agree with this. I grew up rural and was pretty independent by middle school with a broad network of older friends and friends parents to get me rides around the county.

I have friends raising kids in inner city areas, both gentrified and not, and they are all about getting those kids navigating the city blocks around their homes by eight or nine.

I realize those are anecdotes, but suburbs have been repeatedly indicted for a lot of the post-Baby Boomer social issues. Thus, I'm hardly surprised. Suburbs were a massive mistake: fiscally, socially, and environmentally. We're only now really uncovering the entirety of the negative impacts this sort of development had on the United States.

Depends on the suburb, too— I grew up in a prewar streetcar suburb where all the kids walked to school in the 90s (although there weren't really corner stores that kids went down to for milk or whatever). More 'modern' suburbs are designed to only be navigable by a car, and getting to most destinations involves crossing huge deadly arterial roads.

I saw two 10yr old girls on a sushi date here in NYC by themselves. Table full of sushi, eating with chopsticks and catching up with mature conversations. The children here generally seem very independent and well adjusted.