Schools are also a place to expose kids to topics and resources their households may not be able to afford to show them. Schools provide a large range to topics for which students can discover their interest/strengths. They provide initial structure to build to those dreams.

Without schools, most kids would just be learning to do whatever their parents do. That would be the only education they'd have.

What factories run from 9am to 3pm ?

Nothing. But there's a reason western governments offer daycare subsidies as well.

They could be working.