How does sport compare to schooling in the maturation of young people?

This is a very big topic (lots to consider) and I will start by admitting that I don't possess a complete point of view or special expertise.  I observe children and their parents over many months and years, and I have developed some strong ideas based on my observations.
I will begin with a statement: intelligence and independence are strongly correlated.  Children have to learn to take responsibility for themselves and they require intelligence (and suitable opportunities to exercise it) to do so.  
Children begin almost entirely dependent on others.  Hopefully, by the time they exit high school they possess some capacity for independent living.  Schooling understands the importance of independent thinking and action, and education builds this into the learning structures and the schooling environments, generally.  Does sport do the same?  The answer is a categorical, no.  
Young sports people have very little operational responsibility in their programs and even less accountability for progress.  They are told what to do and when.  Homework?  Not likely.  Competition (the educational equivalent of exams) measures progress but post-analysis and feedback in sport is poor.  All learning structures depend on feedback to ensure progress.  Schooling involves a mixture of immediate, intermediate, and long-term feedback.  A comprehensive system of checks and balances, in turn, permits the transition of responsibility and accountability for learning to the student.  The weaker the feedback system, the harder it is to ensure progress and develop accountability.
If we compare sport with schooling, we can say without question that children don't mature at the same rate or as completely.  The big problem, however, is drop out.  Sports struggle to provide pathways after high school but the real enemy is immaturity.  Children who cannot stand on their own two feet when required to, stop.
Our role as parents and coaches is to provide opportunities and to reduce as far as possible obstacles to participation.  Our hearts are in the right place but, if we accept that our kids are not growing up within sport as they should, surely we have to transfer more of the responsibility to them?