This is the stinkiest bullshit I hear from people trying to defend (public) schooling, and please do not take it as a verbally aggressive statement towards you, because it is not.
It's just that saying "school is needed for kids to learn social skills" is a massive pile of bullshit.

Let me rephrase what you just said:
Forcing kids to stay closed indoors for 5-8 hrs a day, sitting down, in silence, without being able to stand up, look outside the window, turn the other side, talk to their neighbor (lest they get scolded by their teacher), together with many other kids their same age which they did not themselves choose, and a grownup whom they need to obey as an authority figure for no apparent merits or reasons, and who will happily bully them into submission (except when a bully kid bullies some other kid, I mean)... all the above is perfectly fine because they get to hang out with "friends" during those 15-something minutes of the recess, and they develop social skills too!

I cannot reconcile the "Outdoor BTC" handle with your stance in this.