I grew up in the 70s and 80s. I was left to my own devices a lot of the time. In some ways it was good -we my sister and I had a close group of neighbourhood friends with whom we liked to play old fashioned street games. (You could, then, you hardly saw a car in the road during the day.). But in other ways it wasn't - I realised that my mum didn't really enjoy spending time with us, she didn't have the patience for it, and preferred to chat to the other mums in the neighbourhood when she wasn't doing housework. (Didn't do my self-esteem much good, although I knew she loved me.) Because of this we didn't actually know much about life, because we didn't absorb her knowledge about the world just by spending time with her doing ordinary things. There were a few dodgy occasions where paedo types lingered too long and close to the local kids and we didn't know what to do about it. We weren't equipped with the skills, despite all our parents assuming we were street-wise because spent all our time playing out by ourselves. We witnessed dodgy behavior by older teenaged boys at an early age eg drinking and smoking. Some of my friends had a try of this stuff when offered.
My dad came in from work and just wanted to read the paper in peace. He wasn't really involved in our life that much or interested in what we had to say, beyond things like teaching us how to ride a bike or attending parents evening.
All that means that I wanted to spend much more time with my own children and be closer to them. And we are a close-knit family. Their general knowledge is really good because they've always spent a lot of time with us and have learned a lot about the world from us just talking with them, and they aren't afraid to ask questions because they won't be told "because it just is", or "because I say so" like I was (don't think my mum could be bothered with long explanations).
I remember on a couple of occasions being put upstairs in a strange bed in a strange house at a party. I didn't sleep a wink, it was very unsettling. I didn't know what was happening or why I was there and when I would be taken home and everything smelled different. I remember the noise of people getting pissed downstairs and finding it quite frightening. So think on, OP, if you think you plan to do things like this. Some kids are sensitive souls and taking them here there and everywhere doesn't harden them up, it just makes them feel insecure.
My kids don't really play out in the street because there are too many cars so there literally isn't the space. There are a few kids that do but these tend to be the naughty kids really and the ones from families who don't really care what they're up to, and their kids don't seem to have many social skills and make a nuisance of themselves constantly knocking when we're having our tea or wanting to do something just as a family. (I'm not saying everyone who sends their kids out to play is neglectful; just that that's what it seems like round our way.)
My kids are older now - 10 and 12, and you know what, they are very pleasant to spend time with. Their general knowledge is great because since small they've spent a lot of time with us and we've enjoyed being able to explain things fully to them when they've asked a question. We haven't fobbed them off with a "I'm busy, I'll tell you later" if I'm reading the paper etc. (But they have been made to wait if I'm in the middle of speaking to a friend, they do need to learn manners!)
One of the saddest things I saw was at a restaurant pre-kids. DH and o observed a girl of about 8 or 9 being ignored by what looked like her mum and friend who were deep in conversation the WHOLE meal through. This poor girl - her face looked so sad each time she was told to get on with her drawing or whatever. She clearly was bottom of the pack in terms of importance, and this is what she will come to believe. Terrible for her self-esteem poor kid. I always wonder how she grew up.
I really think British families need to be a bit more like European cultures when it comes to including children in the family - they are PART of the family and everyone is included. Mealtimes are a family occasion. I do think there is a bit of old-fashioned "children should be seen and not heard" in your post, OP. It's quite an out-dated attitude to put your children's needs last. There is no reason to fawn over and mollycoddle children to the dentriment of good manners and social niceties - a happy medium can exist.