[harshreality]

Plenty of kids whose parents were watching them got hit by cars, because parents can't be watching every second. Kids with a tendency to get carried away and run in front of cars are going to do it even with their parents in view. Better to condition kids not to do a few obvious dangerous things, than to maintain constant vigilance and try to intervene before they do dangerous things.

Also, these days, a parent "watching" their kid(s) means proximity, not awareness. The parent may be within view, but that's useless when they're glued to their phone a good percentage of the time and only glance up now and then.