Ultimate irony is, data shows that time kids spend outdoors has been declining since 1980s, long before smartphones etc. Likely due to parents becoming stricter, overprotective (possibly due to constant "there are predators around every corner!" media coverage)
This trend has reversed in recent years. Likely because... kids have phones. So parents can contact/track them, so more willing to let them roam
TL:DR kids now go outside more BECAUSE of phones