Illiterate is not only if you didn’t go to school. Illiterate is when the lecturer teach you and you didn’t understand his formula of teaching. That’s also an illiterate
Education does not exist for the benefit of students or for the benefit of their parents. It's exists for the benefit of social order. You do not need to be a student or have a child who is a student to benefit from education. Every second of every day of your life, you benefit from education.