I had discussion about it with Cedric Villani once and he told me that was not a disaster because of the books or the material, but the teachers were not good enough.

Eg. when teaching set theory, teachers were debating what should be a perfect representation of a set (is it an ellipse or circle... etc.?) Children were completely lost because of this.

If you don’t draw a perfect ellipse to represent a set then you had a bad mark and so on and so forth.