<< Terrible things happen. They aren't likely to happen.
I think this is the wrong way of looking at this. Most people believe that lightning does not strike people that often. This does not give one has carte blanche to prance around the backyard with a metal rod.
Or, to use less crazy example, my street is relatively quiet and slow. And yet, I still look both ways crossing the street, because you never really know. Individual disposition and approach affects statistics.
I do these things knowing the risk but knowing the happiness they give me outweighs that risk.
Personally, I feel like the benefits to kids of greater independence (developing social skills, learning to deal with being uncomfortable, learning to see things through on their own) outweigh the risks of that independence (sex trafficking or sexual assault, bullying).
Terrible things happen. They aren't likely to happen.