Any system with a test of effectiveness will optimize for better testing rather than better effectiveness.
The very act of measurement undoes the effectiveness of the system. The most recent example for this phenomenon is Volkswagen cheating on their emission test.
This is also evident in education. By having an endless series of tests that span the most creative, productive and formative stages of the human life, we significantly reduce the possibility of producing exceptional humans ready to take on challenges larger than themselves.
We take free humans, force them into a box during most of their prime and then complain about their inability to think outside that very same box.
By focusing on creative / living portfolios for assessments, emphasizing production and creation as markers of learning, we push young humans to care deeply about their work, cultivate a sense of pride, exceptional work ethic and well rounded integrity by respecting their ability to be creators.