These certain things that are learned is the "Body of Knowledge". What Body of Knowledge do you need to watch Jeopardy and what Body of Knowledge do you need to be a contestant. I may not be able to answer all the questions on Jeopardy fast enough, but I could go to the library and look them up, or could buy reference books for home use to look them up, or now use the internet to look them up.
But, there has to be a body of knowledge that is common to everyone and used by everyone in society, or sub-groups of society. And, the Body of Knowledge that a society uses defines the society.
I wouldn’t disagree with your statements.
The key point her brings, from my perspective, is Why does that core set on knowledge have to be imparted via the traditional education system? If you can independently certify that knowledge is in place, who cares about a degree from XYZ high school or ABC university?