It's less about the children and more about the adults.
Most parents that I know are scared that their children will be victims of violent crime. They may trust their kids explicitly and implicitly, but do not trust the world.
The sad thing is that constantly tracking the child won't help with these problems. If someone wants to murder a child, a tracker watch isn't going to stop them. If someone wants to kidnap a child, a tracker watch is going to be ripped off and discarded (along with a smartphone, if they have one).
Pretty much this, my mother would always say I'm not worried about you, I'm worried about others. This went for most things during childhood, walking home from school, driving a car etc
This has gone all the way back to around 2007 as a free roaming kid
Why are we living in a world where we think that kids do not deserve privacy? Or where we think that we cannot trust our children?