The test is not useless, the test's use case is to create a standardised datapoint to pick people to limited spots. That' what the test does, you need to attach false attributes to the test(like measures intelligence) to associate these attributes to the machine and this is a fallacy because although the test probably says something about the intelligence of the human, it does it by measuring meta attributes of the intelligence of the human(like speed of solving problems that the human was supposed to train on).

This is also why there is the "Goodhart's law" phenomenon where in this case students instead of learning physics might start putting all their effort on learning to solve physics tests and you end up with students with very high scores in physics but with no understanding of physics.