From my experience with grad jobs, it's due to the large volume of applications, each of which are different. Some attach cover letters, some detail their grades, etc.

Though it's a horrible method, it means all of the data from an application will be in a standardised format, which can be compared with other applicants, queried, etc. very easily.

If you meet their minimum criteria they can then actually look at your cover letter and CV. Broken system, but they're all the same.

Sane way is speaking directly to recruiters or hiring managers.