I do hear parents saying they don't let kids who are old enough, IMO, to be out and about a bit (say 10-11) saying 'But it's not like it was in our days' or 'There are so many nutters out there'
I'm in early 40s and was walking about 10-15mins to local shops and back and forth to best mates house 10 mins away by age 7 (suburban London). I didn't let out my kids that young mainly as they didn't have friends living that close and there are so few kids of that age around independently I was worried someone would report me! I did start sending DD to corner shop (less than 30seconds away) from age about 7 and a half and I think she only reported to me once someone expressing concern about her (and not calling the police, thankfully!)
I think cars, the biggest danger, were just as big a danger 'in my day' and in fact people generally drive more slowly and safely in towns than they used to (other than those looking at phones
)
I think 'nutters' have always been an infintessimally small risk and there's no evidence there are 'more nutters these days' - just more news channels!
DD started walking to and from school about a mile away from final term at primary as I knew she would need to make her own way to and from secondary school and most people do seem to accept kids walking then, but I don't get why so many don't seem to allow them to do anything unsupervised until right at that moment.