Growing up in a blue collar suburb, we played tackle football for hours in a nearby field in just blue jeans and t shirts, and we played hard but not with meanness. We had one kid who was about 300lbs, and we would push him from behind. He could gain a few years just slowing down, like an ocean liner hitting a dock! Before that age we played in the forests, and even built part of a log cabin until school started.
Then there was my older brother (among 5 kids) who collected the telephone wire the repairmen said he could have and i had a phone system to the kids of other houses about 300 yards thru back yards, with a 6v battery and train transformer. Of course, i also dared tap into my sisters telephone conversation with her BF - once (nothing intriguing). Then there was the homemade gunpowder. And this was with very strict faithful religious parents, with enforced dead lines to be home at, and who employed physical discipline as needed (and it was).
Today it seems like kids only will play for 30- 45 minutes at one things, and many walk down the street alone, some looking fearful or indifferent to others, and only have one or two siblings to interact with at home.
Air conditioning and birth control