No.
Absolutely, 100%, no.
A child could be playing out of sight of a parent, maybe a block away with friends, and get mildly injured in a way that requires minor treatment. Or just crying because of a negative interaction with a peer.
This DOES NOT mean children at a certain age and maturity level cannot be trusted to gain some independence and leave their parents line of sight for short but increasingly longer periods of time.
The GP comment is about a three year old. Not old enough to be playing a block away with friends.
It was when I was a kid.