You asked
I am “just” a parent and can’t supply a definitive answer. My guess is that these are accounting graduates who have taken investment banking jobs. IB jobs in general are very high paying. However because of the high pay, a lot of students are initially attracted to it until they are confronted with the reality of the competition, high stress and long hours. And as an aside, when comparing starting salaries is the very real difference in cost of living and how far one’s salary will go.
In case you are interested in IB I would suggest doing some research, before choosing a school. At U of I look at IBA, the Investment Banking Academy. https://business.illinois.edu/iba/
Getting into the program is competitive, as it would be at any school. Look at the numbers. At Gies there’s about 25-30 students out of a class of roughly 800 students.
As for the ranking discrepancy between Accounting and Finance, the school is aware of it and has been making changes. There are many threads on rankings. All I can say is that my kids didn’t find the Finance ranking to affect their job search and ultimate placement. I also think UIUC’s strong College of Engineering attracts a lot of companies.