Why does it take a degree to be recognized as knowing something?

Is a degree really needed?

Throughout history we have seen many examples of successful people and famous people that didn't have a degree, diploma or conventional education. People like Thomas Edison, Albert Einstein, Nikola Tesla, and so on made some of the most important contributions to science and tech. But if you put on a job application that you didn't complete college or that you were homeschooled you immediately become suspect. Currently college education has become so cost prohibitive that you may never recoup the expense even if you do find a job for which you were trained. In times past an apprenticeship was considered to be far more valuable and more beneficial. Even in my time trade schools were a cost-effective alternative to college. But what it really comes down to is a question that I have asked many times. When a Engineer posts a degree on the wall it does not say that he was a C student, or B student, or A student it simply says that he has a degree, why is that? If I go to a community college instead of a prestigious college like Stanford college, why is what I learned less than if I had gone to Stanford College if they taught the same thing? Why is it if I study books in a library on computer programming it doesn't mean anything, but if I go to a college and pay thousands of dollars to learn from the same books that were in the library, then I know something? In addition if I have the diploma I am supposed to get greater pay for what I learned, but the company I start with will still put me in an entry-level job position, what was the point in going to school in the first place?

Why are we still using a redundant, outdated, Neanderthal educational system that is overpriced, and can't keep up with the advancement of technology?

If we can land a man on the moon using slide rules don't you think we could at least come up with an educational system that is affordable to all and takes into account what you already know or learned on your own and is equally accredited with any other college?