Let's unbox that a bit. In what sense are one's peers cheated when an individual cheats? If the course were going to have 20% A-level students and now has 50%

Let's unbox that a bit. In what sense are one's peers cheated when an individual cheats? If the course were going to have 20% A-level students and now has 50% A-level students, what has been taken from the initial 20%? They were still going to be able to put on their résumé "4.0 GPA from Suchandsuch University."