Should be, perhaps, but the government-- and the parents-- want some sign that their children are actually learning something in school rather than ignoring the teacher or copying their neighbor's classwork, so tests were developed to see how well they learned various subjects, usually at the end of the current term for school but sometimes interspursed throughout as well. It got a little out of hand from there, I'll admit, to make standardized testing all over a very large country, but the original intention was sound.