I am aware that the rules for that are very different from when I was a child and now.

It's got nothing to do with rules. It used to be common sense when I grew up. Also, there are bonding mechanisms in all kids that require feedback from a parent in their early years. This is where your parents attention is necessary. This is also where a kid can develop certain problems if they don't get this attention. My SO sees those failures of zombie parents every day at work. The only thing worse is the parents ignorance.

Same goes for playgrounds that are in difficult areas or conditions of course.

Huh. I spent plenty of time with my parents, and plenty of time without. Yet today's "common sense" says that almost everyone in my generation was raised by wolves.

It's common sense that exaggerations and selective ignorance kills discussions.