I'm not sure that's the case. One example of a teacher scaling is khan academy. I think that something like khan academy could have been done even before the i

I'm not sure that's the case. One example of a teacher scaling is khan academy. I think that something like khan academy could have been done even before the internet, even with VCR's. And automated practice(in math) using computers was available when i was a kid and we even used it through grade 6 , but in grade 7 when we moved to another school we stopped using it. I think the problem is more due to the fact that the teaching profession is conservative(mostly as a way to maintain power, which is not unique to teaching by any means).