If the purpose of a system is what it does, then what does the system of "not going to school" do?

If schooling and learning/education are truly mutually exclusive then who is the most learned and educated person you can point to that never stepped foot in a school? And how do those rare examples compare against the breadth of modern PHD holders?

There are a non-negligible fraction of kids that are kept out of school, homeschooled, etc. If school was as bad for learning as you suggest then one would expect those kept out of it to demonstrate higher-than-average aptitude.

Unschooling works for a fraction of kids, and at some stages of their life.

How big is that fraction? In my experience being around a bunch of home schoolers (and adjacent, and school system), some of whom were more in or out of unschooling, I think it's small enough that it should be a rarely considered option.

There are some kids where it will work _really_ well. I've interacted with a couple. There are a lot of kids where it really doesn't work, especially in a distraction rich environment.

Thanks, I have. And it resonated a whole lot! He was working within a very entrenched system. Systems have a way of achieving equilibria and then all the parts trying their best to maintain it (unions, lobbies etc) School is a practical necessity and there's a lot of good that's possible. It's easier to start outside of the system, but also consequently much harder to scale unless we build tools to help systems to stabilize.

School system was created to increase productivity.

It is also and equalizer. Unschooled kids from bad backgrounds now start even lower.