What's interesting is that beyond a certain threshold (perhaps around the left-hand normal distribution inflection point), further reducing failure rate ends up also reducing the rate of super-success among students in the same classroom.

There is no way to fail in what I'm proposing because there are no grades. Everyone gets feedback on how to improve and students can receive all the help they need to keep up with the curriculum.

1) What if a student refuses to attend school?

2) Can no student advance until everyone has mastered the material?