They discriminate all the time, just in the wrong direction. There are a lot of exams which are written in a way which counts on this mimicking, but in a way which makes tests way more difficult even if you understand the topic. It’s the same problem with remote learning: it’s way easier to cheat on them. In the past 3 years, (except the first semester when COVID broke out) remote exams were way more difficult than before to mitigate this. I had tests which were clearly made this cheating in mind. It was borderline impossible without cheating, they counted on it. At that point, I have no idea why they still tried to enforce any such rules.
And still, I know many teachers who clearly don’t understand their topic completely, they just “mimic” it.
Tests are just an annoyance (that is deemed necessary). Because one passes the university tests does not mean they necessarily understand the topic very deeply, I think it's pretty obvious.
That's actually an interesting point: university students can totally pass exams by "mimicking": not understanding the topic, but solving the exam problems in a way similar to the exercises they learned beforehand. I argue that the test is not perfect at discriminating those who understand from those who mimick impressively well.