I think the question is how much of the grind is necessary. When our oldest kids were very little, we would work on the alphabet and numbers and track milestones carefully. At some point we realized that we could either grind hard at stuff they just didn't quite get, or we could wait a few months until they were older and just tell them stuff and they'd remember it. And obviously it wasn't quite that easy, but it felt kind of like magic at the time. When the kids were ready to learn, they just did, no grinding required.

Naturally, something like playing a musical instrument requires grinding (though it's not grinding if you like it!). But I think other than like, the times tables or the periodic table, there's almost nothing in school that inherently requires a grind. It just feels like a grind, because school is often unpleasant.

I think an average, literate adult could learn basically the entire American K-12 history curriculum in a few months of reading. Most of what passes for history in elementary school could be compressed into... what, a hundred pages, maybe? And high school is another thousand pages.

I think math is the same way. It's a 10 year grind to teach reluctant kids what could be taught to an eager adult in a few months.

I think we'd do much better to try to create eager adults, which I think unschooling is really well-suited to.