By the time I was going out at night (aged 16+, I looked very young, so I'd never have got in anywhere before that age!) we managed with me telling my parents what I was doing and whether I was coming home or staying at a friend's house afterwards.
Daytime I regularly walked over to best friend from when I was 7, we were going to the swimming pool on the bus together by age 9 and walking to park about 15 mins away.
DD is now 10. I would love for her to walk to the park (5 min walk, one small road crossing, one slightly larger road with pedestrian island in middle) with a friend and spend time there without adults, but can't find parents willing to do it. Winds me up no end - she is going to secondary school in just over a year and, like many of her peers, she's going to have to make her own way there.
TBH, social media isn't the problem such much as stupid scaremongering that inaccurately says things are 'more dangerous now'. Uhm the biggest danger is cars, and they existed when I was a kid too - what's more people drove them much faster down residential roads than they do now, plus you were more likely to have people driving after drinking. 'Stranger danger' is probably less likely than being killed by a falling tree branch, but you don't go around avoiding walking under trees. Obviously, you still advise about it. I tell DD she can talk to adults, because actually it's important for safety to be able to talk to people if you need help, but she knows she mustn't go anywhere with them, including ones she know.
As they get older they will have phones, but I don't plan to be awake all hours until they get home, as long as they've told me what they're doing.