Nobody has the competence to change the system, but we all can affect things locally around us. That is what brings real change anyways.

School is tricky. Many people need to work to survive and cannot take care of their children all day. And it is questionable if that would even bring better results since we have separated the communities into isolated families. Children being alone most day with only grown ups around them is also a horrible idea.
Giving the kids to school is often the only option. It is 'free' because we pay it with our taxes. Alternatives then cannot compete in that space anymore. And if they do they are expensive and most cant afford them because their taxes still pay for the public schools in addition.
School is effectively forced unless you are rich.

But what every parent can do is try to compensate. Give your children some room and let them make their own decisions; also bad ones. Don't be overly serious about school grades or put extra pressure on them. Trust in yourself and your children.