Standardized tests, while a great idea on principle, leads to extreme optimizing to simply pass exams with less regard for the material that's meant to be learned. And they can be cheated:

http://www.straitstimes.com/world/extreme-measures-to-crack-...

https://blogs.voanews.com/student-union/2017/02/27/sat-score...

https://www.quora.com/Do-Chinese-people-have-creativity/answ...