No offense, but the idea of having adult level social skills as a child is terrifying to me. Most of the people who I've encountered who describe themselves that way also talk about the burden of from a young age totally internalizing the idea of every interaction being a performance. Every interaction is a new opportunity to try and convince adults that you are worldly and smarter than other kids. That tends to mess you up. Of course, this is purely anecdotal.
"Adult-level social skills" for children was historically normal, and it's only in the past century that children are assumed to be incapable of speaking plainly and intelligently to adults, or vice versa.
You might want to do some looking into the "invention of childhood"; what we understand as "children, teenagers, young adults, adults" is a fairly modern way to look at "stages of development". In the distant past, children participated far more comfortably and fluently in adult society than they do today, when they're sequestered away.
It is very difficult to see any representations of this in the US, where most children are in school, so I'll point to examples in fiction: fictional novels or movies where the protagonist is taken confidently through an unfamiliar city by a child who seems to know every location, has a sleeping place, weapons, a method of finding money, and a network of friends. In these works of fiction, the child is almost always a semi-homeless "urchin"; but this is mostly because modern writers can't conceive of a child that capable without also assuming that the child's parents must not be involved in their life, because modern people equate "parenting and raising children" with "making sure children only ever do child-appropriate things".
My question to you: what do you think it would look like if two loving, attentive parents tried to raise a kid with the confidence and skills of those fictional street children, but also actually fed them and gave them a place to live?
It is very likely that the answer to that question is far closer to the way that children used to behave and live than the way that children are today.
I also recommend looking at old tests and study material (pre-1900, ideally pre-1800) for young children. Children can read, figure, write, and remember at a level far superior than they're assumed to be able to today, and that goes for adult socialization as well.
To be honest, I just saw a really phenomenal dark comedy routine about somebody who was adept at socializing with adults at 6 or 7 and I've been thinking a lot about that dynamic and the dark side of being a precocious kid. I wasn't that extreme, but I related to some of it, and then I ended up projecting that onto your description of home school kids. And yet, this guy wasn't home schooled. I think those are totally separate issues. Would be an interesting separate topic, though.
I went to a brutal and oppressive public school in a 3rd world country yet I was able to interact with the adults around the age of 11-12. I was always one step ahead of my 3 years older sister. I think a lot of this was I was jealous of her getting attention from thrme other adults and especially my parents from an early age. I self learned how to read and write when I was 4, exactly at the same period she was learning at school.
This resulted in quite a bit of psychological problems for me, since I always thought my peers are stupid. You start to isolate yourself, and this trying to impress adults changes form into trying to impress your boss etc.. My parents had no idea of course, so no use to blame them. But fir my own kids this is something I'm trying to keep an eye on. I think it is possible to distinguish what is genuine and what is for getting positive confirmation and attention. The best measure is the capability to entertain yourself. If a kid is able to not get bored when with adults without interaction they have a healthy amount of self confirmation.
So the show I saw is not yet available in a recorded format, but I recommend checking out Gary Gulman's comedy special The Great Depresh. And if they do ever record the live performance I saw, I really recommend you check that out. Somehow both funny and extremely enlightening, and right on topic with what you're saying.
