Grades are the measure of kids are progress in what learning and what knowledge they actual have, you can call it something else like in Montessori where they change the system of grading where they use terms like mastery but they still have a system in place to track progress.
I think you're confusing grades with teaching to the test, thanks No Child Left Behind btw, here which okay is a very valid point but end of they day standardized tests are a way to measure your actual grasp of the material being taught. Sure, how you get there needs adjustment at least in America where our math scores and reading comprehension scores are abysmal but to say it's grades is the issues is kind of reductive when it's such a more complex issue that involves how we teach, how we deal with disparate incomes, new thing is low enrollment, and why the hell aren't we teaching phonics when whole-language and three-cueing methods are proven to be ineffective for literally decades now.
There's a reason why colleges are moving back to requiring ACT/SAT scores in their applications again because in particular with items like math, kids were graduating and then finding out that they didn't understand basic concepts like Algebra.
Also, this conversation has nothing to do with the article and AI.