Maria Montessori was a genius so ahead of her time we still haven't caught up with her. Few schools, though, adopt her principles past middle school.

And interestingly enough, though her ideas were focused on the poorer classes, it's the wealthy who've adopted them for their own privileged - and expensive - and private - schools.

https://www.newyorker.com/books/under-review/the-miseducation-of-maria-montessori