And why is that important, since we've managed to survive without that capability for several tens of thousands of years in much worse circumstances than a modern city?
So 100 years ago, a guy kidnapping your daughter (just an example of anything that could only be resolved by you knowing where you daughter was) isn't a serious worry, since that's a 0.01% risk as opposed to the 2% risk your daughter gets sick with whatever and dies.
Now, it's that same 0.01% risk compared to a 0.00003% risk thanks to advancements in modern medicine, so we worry about it much more.
Makes sense at first, but I don't think we are. I see other cultures (including western ones), and even the US at 70s and earlier, that don't do the same "everything" at all.
I think what we are, in some countries, is conditioned by hysterical media and hysterical society, to over-protect our children to the point of social pathology.