I'm curious as to why you think whatever benefits society may gain from compulsory schooling are so important as to justify in your mind using violence and the threat of violence to force kids into attending school and to force parents into sending them there?
Would you be happy being forced at the point of a cop's gun to spend twelve years of your life working at something because some random people decided that forcing you to do it was beneficial to society?
Maybe schooling is beneficial to society and maybe it's not, maybe it's even beneficial to me personally, but I can't see that as a good reason to require it by law given that all laws are enforced by violence.