They want to know you have enough money to afford college.

My headcanon is that college started out as a way for the wealthy elite to get their children to socialize with and breed one another to produce the next generation of social elites. These aristocratic objectives were highly correlated with the ability to successfully pass entrance exams and perform scholarly tasks, until the the “college for everyone” movement of the late 20th century (e.g. the GI bill). Then, the next generation of aristocrats collectively sent their children to an elite subset of colleges (e.g. Ivy League schools) and upper class companies filled out their managerial job slots with graduates from these colleges. At some point, I believe the wealthy elite will dispense with this academic charade and simply manage their own private dynastic dossiers for managing the breeding and marriages of their children.