I do feel like we as a society are moving in the direction discussed by the article, as a general trend. But this is not my personal experience. We live in typical suburbs, and we are lucky enough that our street has a bunch of like-minded young families that let their kids play outside. Our street really feels like what you would imagine if you were thinking of a typical street in the 1960s. Kids aged 5 to around 10 playing ball in the street, going in each other's yards/houses, etc. There's a Catholic church less than 1km away, and at 6pm every day the bells ring. All the kids go back to their houses for supper when they hear the bells. It's great.
There's a kid (7-8 years old I think) a few houses down that carries a walkie-talkie with him during the summer. He'll be out for several hours (probably not farther than 10 houses away from his own house), and his mom checks on him every now and then using the walkie-talkie. I'll buy a set for own kids this summer for the exact same purpose.
The only thing I'm kind of scared of are the cars, because they tend to drive too fast (for my taste) and kids tend to not always look when they cross the street when they're too excited playing their games.
Edit: I just remembered that a few years ago, the cops showed up because there was a complaint about our kids being left unsupervised. They were playing in the backyard, which is completely fenced off, while we were inside cooking supper. Our kitchen window faces the yard so we could see them, and the window was open so we could hear them. At least the cops realized that the complaint was BS and didn't even come inside to check for anything. We live in Canada.