Earlier quoted context omitted.
Here you have a 'counterdote' : I am 43. After the first year of high school ( I was 13 ), we were allowed to travel to the other side of the country by train, sleep in a youth hostel and return at the end of the next day. This is NL, the other side of the country is only 350km. When we tell younger friends, they refuse to believe.
America is a wholly different place. I was born in the mid-80s in Moscow, Russia, and moved to America when I was ten. Before I moved, I was regularly taking the subway, with transfers, to school - by myself. Here in America, I had a coworker a few years ago who literally would not let his double-digit-aged children cross the street to school by themselves. It's a weird fuckin' place.
Adults are part to blame as socially, parents are frowned upon for even letting their kid take the bus instead of being their private chauffeur. (Granted I live in an area where private schools are more popular than public. But I've seen this same thing play out in the exurbs with mostly public schools.)