We can't be employed or be adults or get married at a certain age according to law. Do you think it is good enough for us?
We all know the age restrictions according to law. These laws are mainly to protect us to get educated from childhood, and the law is not old in our history at all.
I think we can't really accept any knowledge without enough experiences, for example, it is hard for us to remember or understand that H2 can be burned in O2 and become H2O if we never see or do the experiment in person. It is very hard for us to learn ourselves and our society and learn to think if we have to take all of our time to learn text books and go to colleges or universities.
Actually it won't take us many years to learn to read and write and use computer, and we could read anything we need or want after that. Do you think we are healthier and if we could go to work and get married earlier?