Here come all the anti-testing comments, as expected. In the smartist era and in the meritocracy, we need more testing , not less, to help help identify gifted and slow students. Whether it's an IQ test or a proxy such as the SAT, testing is the best way to assess individual general cognitive functioning for large groups of people, as well as identity exceptionally talented individuals.
More testing raises the stakes for everyone, meaning that the overall population becomes better educated and competitive, in order to do well on the tests.
Furthermore, many smart students find coursework boring an get poor grades, but excel at standardized tests, because they already know the material.
There was a fascinating ted talk awhile ago about how standardized tests, contrary to being useless as often ascribed by the left, can predict lifetime outcomes such as wages, being published in a journal, level of academic attainment, and so on.