In any case, even if you can still find some occasional examples of people allowing unsupervised play in some situations, it's definitely unacceptable to simply send the kids out and tell them to be back for dinner, the way it was normally done some decades ago.

One of my professors lives in a cul-de-sac where literally every house has ~2 kids of roughly the same age, and so most of the parents allow their children to just go outside and play with the gang until dinnertime. I believe at least one of the parents is typically watching, which is also a departure from the old days.

Hearing him describe it to the grad students / other professors, though, it was clearly a "this is an abnormal neighborhood which is like where I grew up, which is fantastic," and he's the only person I know of with a neighborhood like that (though certainly similar neighborhoods must exist).