As a child I spent most of my day outside playing and not using screens and I still had myopia as a kid
We’re talking about probabilities and statistics over large populations. Not every child who plays outside will avoid myopia, like yourself. But looking at the population, the expectation is that children who get more sunlight tend to have a lower incidence of myopia and weaker myopia.
Both my parents are past -8, maybe -9 or -10? I forget, got some realllly thick glasses.