The tests are a lot different than school exams based on coursework that you study for. Those exams you are taught content and told what will be on the test and how to prepare. There may be weekly quizzes, a midterm, a final, essays, graded homework. You receive back graded each quiz and exam that has marked exactly what you got wrong so you can focus on areas you have problems with for the final.

With standardized state tests, IQ tests, SAT/ACT, you don't get any feed back. For standardized state test you spend a lot of time on the test and are never given any feedback at all. When I was in school I just stopped taking them. I would sit there and not fill in anything. Why should I? The SAT was more of the same. I would not receive any feedback about what I got wrong and I have no idea what the questions will be or what I will be tested on. A lot of students then say why bother and just sit and fill in all A bubbles or leave their sheets blank. There is no point in studying for such a test as you have no idea what will be on the test.

Now the ACT is better since they have a test question bank and if you take it enough times you'll see most of the math and grammar questions. But the reading stuff is all random and lots of the questions arbitrary with even the authors of the excerpts used saying they have no idea what the correct answer is supposed to be about "what was the author's intent". Still how many students know any of this? Most teachers don't, fewer students.

With "high stakes" state standardized exams so many schools in the US spend most time in class drilling and prepping for these that everyone loses interest. It is incredibly boring prepping for this stuff and they push test prep for over 10-13 years, badgering the students about how important it is for a test they will get no feedback from, and which is taking up the majority of time in over a decade of state education. Everyone sane checks out and gives up.