> Generations of kids survived without their parents needing to know their location at all times.

Did they? The problem with this sort of claim is that it often turns out to be false. "We didn't have X and somehow we survived" often omits the fact that mortality in given demographics has dropped significantly since then. The people making this statement are survivors, and the ones who haven't survived don't speak up. Can someone back up this claim with data? My (very) quick search brought up only infant mortality rates.