I’m quite sure my late parents would never have bought bottled water under any circumstances!
As a child I drank mainly cold milk, with Ovaltine as a treat.
Going out to play as a child, or into town with friends as a teenager, none of us took a drink. We’d go to a café and pool resources to get a drink to share, or just find one of the water fountains dotted around. As kids playing on the common we’d drink water from the stream from cupped hands, we all survived despite fishing for tiddlers and sticklebacks at the same shallow spot.
When the family had a day out in the car, my father would always stop at a pub halfway, he’d go in for a beer, my mother and I sat outside or in the car and he brought drinks out, a shandy or snowball for my mother and always pineapple juice for me (still my drink of choice on my rare visits to a pub)!
They didn’t do picnics, but would find a café for lunch.