Your last point is made explicitly in the article when it calls school a babysitting service. If you take out the explicit goal of education away from school, you get tax-funded babysitting. In many schools, the funding is low enough that the education system is mostly that.

It takes a lot more money to actually educate kids in a way that gets them to their maximum potential. That’s why affluent families have that rich education outside of the system: society doesn’t spend enough money on it.

While the education system has some good aspects, with a couple of them even being education-related. The focus of society should be on reducing the number of children with bad home lives.