If cycrutchfield is correct (in https://news.ycombinator.com/item?id=38719752 https://news.ycombinator.com/item?id=38719752), all the doctors put together get 1

If cycrutchfield is correct (in https://news.ycombinator.com/item?id=38719752 https://news.ycombinator.com/item?id=38719752), all the doctors put together get 10% of the spending. Insurance overhead gets twice as much as the doctors? That's insane. That's a huge amount of overhead that could be dramatically reduced with single payer. Still, that's only 20%. Would single payer reduce the other 80%? If so, how?