Children in the camps of Idlib answer the question.
They don’t go to school because their school was bombed, destroyed.
Because there is no school where they are camped.
Because they can’t get to the closest school.
Because there is no space in the closest school, or they have no family records showing who they are and can’t register.
Because of airstrikes and shelling.
2,100,000 children in Syria do not attend school.
Education is a basic right for all humans, declared in Article 13 of the Universal Declaration for Human Rights.