In the US at least, we've gotten to the point that kids under 10 are rarely trusted to be alone and parents risk neglect charges by leaving them. Even the 10-13 range could be a risk. The problem is if someone calls the cops or social services, enough of those departments will take it seriously that as a parent, you really don't want to risk it.

It's a problem, because it's raised the bar for expected supervision effort, likely far beyond what is really needed.