"But very few are going to learn much of it outside of a classroom."

I'd say that pretty well nothing of that I learned in a classroom, and that would have been true of all my contemporaries. The very idea of learning that kind of stuff would have been pretty well unheard of when I was at school - or indeed since schooling had been in existence.

That doesn't mean that trying to deal with those things in schools isn't worth it. There,s an appalling level of ignorance (and indeed in some ways it seems to be growing - "knowing" things that are false is the worst kind of ignorance.) But there are real limits to how far that can ever be done through classroom learning. The crucial thing really isn't providing factual information, it's preserving curiosity and helping children improve their ability to satisfy that curiosity, and recognise when the answers they get don't make sense.