You are very clear. To put in abstract terms: you argue that the education process carry some value which is difficult (or even impossible) to test, making it inherently more valuable than the certification process. I can't say I completely agree with the argument, but I can understand it.

I still think that the tests, if elaborated by entities fully dedicated to them, could grow to be way more advanced than they are today. But even in the case where this growth does not happen, having separate entities dedicated to perform test-only certification could be beneficial.

By the way, if you still read this: suppose you have student A and student B. Student A attended to all classes, did exercises etc. but failed the tests. Student B missed all classes, but passed every test. Do you think student A should be certified? What about student B? Who would you hire?