In an ideal world, the goals of education would be to...
First, aid the individual in discovering what his native traits are -- the who and what I am.
Second, to apprehend the nature of 'the world' in its physical and social manifestations.
Third, to aid the individual in finding a congruent path between his nature and social expectations.
Fourth, to discover what is for him good work, and acquire the necessary skills.
Rats. Just noticed that we don't live in an ideal world. Well, that's a problem, but we can still pursue my Four Goals. (Note: This kind of education can not take place where society is in a state of advanced deterioration.)
Primary school is still... 'primary'. Education for children through 6th or 8th grade is the critical phase. "High school" (9-12) really should be quite academic, but still not overly structured and restrictive. By the time one is 18 they will, one hopes, be reasonably insightful, reasonably capable, and reasonably socialized individuals. Of course, there is variation.
Acquiring linguistic skills (reading, writing, listening, speaking) and numeracy requires structure. (This must begin in infancy when the parent is responsible for development.) Children need quite a bit of freedom (within safety limits) to discover who they are, at times without adult direction.
Apprehending the physical and social nature of the world again requires structured learning, as well as unstructured interaction. Children need to be free to be who they are becoming. ('becoming' can be a very messy process; clean-up crews on hand?)
A criticism: Parents aspiring to produce accomplished children fill their days with rigid school schedules and extra lessons in music, dance, sport--all sorts of structured activity. This runs counter to the child having unstructured time for personal discovery.
Finding a congruent path between personal identity and social expectations requires ethical training. Some social expectations are good, and some are not. What one likes and dislikes isn't a sufficient guide. Individuals need a grounding in right and wrong as well.
Finding good work (work that one likes, and which contributes to both the individual and society) is a daunting task--made more so by the state of advanced capitalism in which billions of people must operate. There is 'good work' available, but not nearly enough to go around. Most people are going to find 'good work' hard to find.
I think children benefit growing up in a permissive -- and reasonably safe -- environment; what is permissive for young children may not be appropriate for older children, and visa versa. Actually, this is true for adults too. We like being able to explore possibilities without constant restraint and prohibitions.