The reality is that children (and actually teenagers too) need care and structure and can’t just be left for days and weeks on end to fend for themselves.
that would be why a 5 or 10 year old are not legally allowed to move into their own place or left in the wild 
Supervision, pastoral care, basic skills, life skills, education, it's all YOUR job as a parent. Teachers might be trained professional teaching about specific subjects, but it's outrageous to completely remove yourself from your own role! Parents are in charge of education!
Us adults might go on various technical course for work, that's education, but you don't expect your boss, the government or god knows who to teach you how to make your bed, pay your bills or cook diner...
Yes, you remove the hours normally spent at school from your need for childcare, but the schools are not a babysitting service. They are not there to care for sick children that parents refuse to keep home.
We should concentrate a lot more on what education is provided to the children. Kids are not sent to school to free time for their parents, they are there to learn, to socialise and still have a childhood.
If you want someone else to be in charge of structure, routines, pastoral care, general education, life skills, then get a nanny. Don't waste the teachers'time who are there to teach my kids and yours, not do your job.