I've met a lot of people who spent most of their lives at school and still end up with social issues. I understand where you're coming from; just pointing out that school is not always good socialization or the only way to socialize children.
Typically it is the option within reach.
We've eradicated free ranging & natural adult-free peer time. What's left are adult-built programs. They're artificial constructs and they take real time and money to be reliably available.
I had 5 kids. I spent 10x time (per child) parenting, compared to my parents. My kids had a busier life than I did but they were still shortchanged.
They've also almost universally been incredibly smug, self-righteous people who talked to everyone around them like we were unwashed, unenlightened souls who were to be pitied for having gone through a public school education.