Plato's academy (and most of the ancient academies) were not built to "find out who was the best" at X or Y. They were built to a) teach current ideas and b) develop new ones.

The problem with post-scholastic (and I would argue even scholastic) thought is that we've mixed up the two roles. Grading (as we know it now) is a relatively new invention... probably invented around the late 18th century at Cambridge.

And yet these non-sorting educational institutions still produced Newton, Galileo, Augustine, and so many others.