Who will take care of the children who are not answered after school?

I live in Xingsha, and no one answers. Sometimes I want my children to go home by themselves. My family lives in Tiejian, not far away. But the teacher doesn't agree with the children going home by themselves. I don't understand. The school is so big, it's good to stay at school and wait for parents to pick it up. It's good to finish school so early, rest for two hours at noon and finish school at 5 pm.