Some people, such as Bryan Caplan, believe that college is mostly about signaling.[0] The idea is that most of the value college provides for individual students is to indicate to society that the student can jump through all the hoops necessary. It's much less about what the student actually learns in college. Essentially, college is mostly about being a filter - to weed out those that can't make it. This line of thinking would also explain college acceptance tests - they are the same type of filter, but applied before college. It's there to keep the college prestigious, so that more people will try getting into it, which will allow them to only pick the best of the best.
I think there's a lot of merit to the signaling idea, because a lot of what you learn in college doesn't have much practical value for the vast majority of students. College entrance tests are just one part of this whole process.
[0] https://blog.press.princeton.edu/2018/01/23/bryan-caplan-on-...