I agree up to a certain point. I think in safe countries, they can go by themselves and maybe accompanied by other kids, education is key, in case something bad happens if parents teach them, they will know what to do and help each other.
Now... there are countries and places where they simply can't go on their own, for example if I was a parent here in Venezuela I would be very afraid to let my kids go out alone, but if I lived in Japan or Europe I would let them out with no worries. My mother was one of those helicopter parents haha, I had problems because of that but also didn't become a criminal or got into drugs like a lot of teenagers here, but it's a double hedged weapon of course, it has been difficult for me to become independent, I guess for those people who were raised that way it was easier.
In a completely safe country and society is very common to see free range children. In my opinion, balance is they key :)