What other structure is there? All knowledge and skill is based off of more basic knowledge and skills. If someone doesn't have a grasp of simple addition, calc

What other structure is there? All knowledge and skill is based off of more basic knowledge and skills. If someone doesn't have a grasp of simple addition, calculus isn't going to make much sense. That's true at the lowest levels and the highest levels. Now if you're arguing that the way we test if someone is ready for the next level of a given field is done poorly, that's different and there could be a strong case for it depending on the field and school.