The first ten times I read a headline like this, I thought it was just Americans being American, but then it started happening elsewhere too.

I do believe it has to do with the development of suburbs, which has to do with prioritizing car infrastructure over anything else.

I live in a small town, less than 20k people, and even here, the developers of the most recent suburbs have chosen not to have pedestrian sidewalks at all. They'd rather sell those square meters as building lots. It makes sense. Nobody is requesting a sidewalk to upkeep just so they can walk to their neighbor who they don't socialize with anyway. The kids from these places never even get to learn how to walk a street safely, because their parents insist on driving them everywhere for their safety.

The older suburbs were made in a different time when politicians had expectations of cities growing and developing over time to have their own centres and shops and what not, which would require facilitating traffic passing through and local accessibility. The modern ones do not. They know now that modern suburbs are dead end appendix streets that never develop because people drive to the strip malls instead of walking to a local store, so there's no reason for the municipality to require silly things like pavements, bike paths and playgrounds and such.

I do notice that more young people are currently choosing not to buy houses in those areas, but it is going to be difficult to fix the layout once it has already been made, because there really isn't room for improvement between the lots.

It kind of is. Kids are expected to go places in cars.