In 2010, the US government spent $900B on education. If Khan can reduce the number of teachers needed by even a few percent, that's a HUGE savings.
Fully agreed with the conclusion. Staff compensation (including SUBSTANTIAL nonsalary compensation) is a big part of the budget of any school. Making the work of teachers more efficient (in the economics sense of "efficient") helps free up money for other worthy purposes.
Another comment to your comment doubted the figure, I think because you wrote "US government spent" when you perhaps meant "all levels of government in the United States spent" so much money on education. Most spending on schools in the United States is from state taxes (as in my state) or from local taxes (as in some other states), as I'm sure you already know but which may be news to onlookers from other countries.
"The U.S. has more than 14,000 public school districts and spends more than $500 billion on public elementary and secondary education each year (combined spending of federal, state, and local governments)."
in 2010, the US Department of Education budget was $47 billion [1]. That's between 1-2% of the total budget. The problem with education in the US is not cost, and even if it was, the solution is not 'get rid of a few percent of teachers."
In 2010, the US government spent $900B on education. If Khan can reduce the number of teachers needed by even a few percent, that's a HUGE savings.