The entrance requirements were either university-wide or college-wide I dont remember exactly. But certain departments are more selective than others because of who applies. UIUC’s physics program is ranked much higher relative to the Math or Stats program. (Both are still good nevertheless) Generally because of this, Physics gets more really qualified applicants and they still have to choose who to admit. Physics is technically in the engineering department too despite offering a degree in LAS. As far as I know though, the difference is pretty marginal between the three majors.