Well, in many suburbs there is no pavement (in Canada at least). Children play and too many times they just run into the street or just walking and without thinking move 1 meter sideways. Also some playgrounds are very height like 2-3 meters and children fall from it (like flat with back and head on the sand).
Anyways, maybe I need a therapy to calm me down.
This is a modern invention. Kids of that age routinely explored the world on their own in the before time. Then social media happened, and everyone thinks that everyone else is a risk. Everyone thinks they're doing good when they call the cops upon seeing a child by themselves.
I went to kindergarten alone every day at age 6. Almost everybody on my street did that. It was a 1 km walk. At age 7 I walked every day alone to school 2 km away and I remember it took exactly 25 minutes.