Hell, when I think about it....if "I" were a child today, and my parents raised me like they did back in the day....they'd be under the jail, with child protective services taking me away LONG ago....
No cell phones...and during the summers starting when I was a teenager....my mom started work again....so I'd be home alone all day, running around the neighborhood with my friends, playing all day.
We rode bikes and skateboards miles....played in the woods near our subdivision that hadnt' been developed yet....built forts, built skateboard ramps (the local house constructions "donated materials").....neighborhood pool, etc.
When I was very young, I had to call home about every 2 hours from a friends house....but other than that, I'd leave at sunrise and my folks generally didn't see me again till dusk and dinner, where we all ate together.
I got a job at 16yrs....I've been working ever since. With a little help, early graduation, I bought my own car my senior year in high school....a '78 280Z....fun!!
But yeah, no supervision was how we grew up, my friends and I are all older adults now, many with kids....we got into trouble and mischief, sure, but nothing that stopped the world and we learned how to deal with people and the world.