OK, let's think about what your life would be like without school.
Could you do the following:
Fill out a job application.
Balance a check book.
Drive a car or even get a driver's license.
Obtain a job that pays above min wage.
Join the military if desired.
Purchase a house, a car, or get a loan or even rent an apartment.
Shop intelligently for anything.
Travel on a plane, bus or ship or use mass transit.
Read and understand a book.
Use a computer.
Ask an intelligent question, give an intelligent answer, carry on an intelligent conversation.
Need I go on?