The only thing to do was play which we did prodigiously - I was part of a large mix-aged group (6-12 kids, 5 years age difference) and we would play everything (sports, house, building things, demolishing things, raising stray animals, foraging fruit, fighting other kids). It was a great childhood and neither I nor my childhood friends (most of us are still friends, even across continents) would trade it for anything. Interestingly, it was almost the same childhood my mom and dad had.
My sister (the de-facto leader of our group) now has children and their childhood could not be any different - constantly shuttled from home to school to organized activity. Play only for a bit under heavily supervised conditions (ie, birthday party at another kids house) and filled to the brim with tablets, phones, computers etc.
I feel very bad for my nephew's effective lack of childhood, even more so because it seems that doing something differently is a big social taboo. My mom, siter and I have talked about this, and my sister described being almost powerless - who would they play with? Where? What are other parents going to think? etc etc.
When I go to places like rural Belize or small-town Costa Rica I see kids still playing and I wonder if that's not the best place to raise a small kid (4-10 years old).