I don’t think anyone is encouraging total unstructured freedom.

I went to a school without grades. It encourages cultivating a love of learning. There was concrete feedback on quality of work and assessments of knowledge (tests). But no public grading scale. It’s been awarded 3 blue ribbon awards and consistently outperformed its grading-based peers.

I know it's a lame answer because I can answer it to most new schooling concepts

Cohorts.

If all the students you schooled with could easily come from the other available systems and your school could only expel them at the same rates as the other schools I'd be happier.

Actually the modern concept of a school was developed to train people for industrial jobs, where they would have to follow instructions and a schedule set by their superiors -- hence the strict scheduling, the rank-and-file arrangement of classrooms, and so forth. Prior to the industrial revolution most children did not go to a formal schools, and would receive their education from parents and tutors, or by some other ad-hoc arrangements. In some parts of the world it was common for traveling teachers to board with a family for some time and educate the children.