They are assigned to you by a human with natural human biases and flaws. The SAT test allows those students who have had a difficult time with the current high school system to have a fighting chance at a decent future. Students with good grades and outside activities do not need to panic because their SAT score, if good, will only help them, and if bad, will be overlooked. That could cut back on the issue of tutoring. It is an equal test that is given to all students.
Some high schools are more difficult than others.
If you get a few really tough teachers in a school with no tutoring provided and get Bs, the SAT balance things with the kid who goes to the really easy school with good teachers and free tutoring. The SAT provides an equal playing field for all. There needs to be an exam that international students can take with a chance to get a good grade. You should have a choice and those who do well should get money off or some other reward. I believe that the entrance exams to get into college aren't necessary.