I should add a disclaimer to my condemnation: I have seen some kids who did well "home schooled", but they were what Americans call "unschoolers" where the parents didn't teach them at all and instead they are expected to be out in the world learning through social interactions with non-family. Most of them found real work to do, had fun playing with kids their own age in the area, helped care for younger kids and learned about different topics they ran across. They picked up responsibility and deadlines through real work, and research through being interested in things.
Around high school they'd often take some classes at high schools or community colleges, but instead of being less socialized than the other kids there they were more socialized and were already used to having to interact with other kids in unstructured environments. Instead of spending time with their parents or in structured activities (home schooling) or just with kids their own age and structured activities (traditional schooling), they had the chance to learn from unstructured social interactions with everyone from infants to adults.
I think the concept of nuclear families is pretty unnatural, but so is a society stratified by age. Add to that that most teenagers aren't doing anything that matters and you get the frustrated, pointless bickering of high school. I don't think structured activities combined with opting out are a good substitute, but it is possible to provide teenagers with meaningful work, personal agency and the time and opportunity for unstructured social interactions.
The problem is that that requires giving up a lot of control over children (and the myth of "child" as vastly different than everyone else), and almost no parents I've met are willing to do so. They're happy to drive to 1001 piano lessons and organized play dates and craft projects, but not to let their kid go take off through the neighborhood on their own. They don't want their 14 year old to be forced to sit in class, but want to know where the kid is at all times and make sure there is always a trusted adult present. Kids are supposed to fear strangers, not interact with them. They need to be taught, not discover things for themselves (especially if what they discover is different than what you believe!)
There has to be a better way to keep adults from exploiting teenagers than locking teenagers away, but we haven't apparently found it yet. Everyone wants to shelter, protect and control teenagers. If we take that as a given, at least high school gives kids the advantage of numbers over adults and the chance to learn from one another on the fringes. It doesn't mean it is ideal, but I do think it is better than telling kids they don't need to interact with the world.