But many things are compulsory in schools
Reading, 'riting, 'rithmetic.
Gym
Language
English
Social Studies,
Science
Uniforms in some schools
ROTC in the HS I attended.
The parents have a choice of schools, at least here in Mini Snow Duh.
Don't want you child to were a uniform a school (yes, these are public schools), choose a different one.
Don't like mandatory religion class, don't send to a private religion based school.
Don't like the curriculum, choose another school.
"All men are like grass, and all their glory is like the flowers of the field;
the grass withers and the flowers fall, but the word of the Lord stands forever."
1 Peter 1:24-25