I have struggled with the same feelings about the YA stories I write.
I believe an emerging trend in YA fiction is a return to exactly the sort of worlds you mention. Where kids are free.

The problem has always been about how to let your characters have freedoms that 'real' kids do not have. For this to occur, the 'suspension of disbelief' has to happen for the WRITER who is an ADULT. I don't think young and young adult readers have that problem. For instance, when I write I tend to think, 'why isn't this kid at home doing his homework? He'll end up having to repeat Grade 8.' I am convinced that young readers easily ignore such things.

I have tackled this aspect of the story by having a kid whose widowed mum is always at work trying to make ends meet at the start of the story. Then problems arise when she no longer has to do that and in the main character's mind she seems to be constantly on his case.

It is still fantasy-based, contemporary speculative fiction just the change in circumstances adds to the conflict.

As I mentioned, I do think that YA are tending to be drawn toward the 'old-fashioned' worlds where school is an aberration and all life occurs in the summer months. (Just realised that i am describing the exact opposite of the HP novels, in which all 'life' happens at school and 'the holidays' are almost ignored. -- still of all the kids at school, the HP triad of Harry, Hermione and Ron have freedoms the other kids do not and for no good reason except that they may be somewhat indulged. Perhaps it ties-in with the common childhood fantasy of being on equal terms with adults. They believe they are right and the adults sowly come around to see that they ARE right.)

Just some thoughts.
I am interested in what possibilities YOU see in tackling the problem.

I'm not sure where you're getting your rules from. Perhaps you're exaggerating the age, perhaps not, but I don't really know how to answer the question if I don't really understand what you're talking about.

The crackdown is doubtless more severe in neighborhoods where there's been a kidnapping incident. In Northern Idaho and the neighboring regions of Washington State where the horrible Dylan and Shasta Groene case took place, a mother of young children (I'd say under age 8) was interviewed saying that before her kids "were allowed to play only in the yard, now it's only in the yard when mother is watching"--meaning the mother can't do ANYTHING else, except, presumably, work in that part of the yard where her kids are, at ANY time when the kids want to be outside! Which is as abusive to the mother as to the kids, if you think about it.

Hypervigilance is the condition of maintaining an abnormal awareness of environmental stimuli and scanning for threats. It is sometimes characterised by intrusive disturbing thoughts and mounting anxiety. It can be promoted in parents by repeated exposure to 'threats' as reported in the news and popular media, indicating that these threats, ( including such things as sexual, mental and emotional abuse, abductions and physical harm etc), to children are more common, widespread and frequent than they really are.

Having said that, these occurences are more widespread and frequent than most people realise. The hypervigilant parent will often know or have exposure to children or families where one or more of these things have occurred. A sense that the general public are 'less aware' feeds the syndrome. To the chronic sufferer, children roaming the streets at dusk may be seen as evidence of parental neglect, ignorance or lack of parental skills and confirm their views that the threats are real and exist just outside their front door.

Most parents will experience periods of hypervigilance, often as a result of some catalysing negative event like the ones you mentioned. As a father of a fourteen year-old girl, a twelve year-old boy and an eight-year old boy, I know I have.

Edit:

Also there is a tendency for parents to give children almost boundless permission/indulgence early in their life. As disturbing or destructive behaviour occurs, parents tighten the controls and rules. This reads to the child as decreasing freedom and loss of favour.

Evidence suggests that little children should have the tightest controls and the strictest rules and as they mature and learn how to make well thought-out, sound decisions, freedoms should increase and rules relax. This reads as increasing freedom and promotes a sense of being trusted.

The point I want to emphasise is that kids in books tend to have more 'freedoms' than real kids do, or imagine they do. That is part of the escapism.

Okay, going back to what was being said about "controls" and so forth, I tend to think of it in terms of the amount of help a child needs to do things. An infant needs a lot more help than a child of two, who needs more help than a kid entering kindergarten, and so on and so forth.

Admittedly, my theory leads me to restrict privileges ever more as a child gets older. The child has to become more independent.

As for fantasy, I think there are lots of possibilities for entrance to "other places and times" within the house and yard.