So on my soapbox, I want to be clear. Homeschooling IMO, done by parents
who value education, IS superior to a traditional classroom 5 days a
week.
From a purely academic point of view perhaps, but school teaches so much more than that. There's all the intangibles; how to behave in a group, how to socialise, how to play team games, how to react to authority, how to smoke behind the bike sheds. The list goes on.
I would have hated to be stuck at home day in day out learning off the same people, espeically if they happened to be my parents. That would be more than a bit weird. . And as much as you wish it, it's impractical for parents to know every subject to a high school standard. That's why schools have different teachers for different subject.