The general diversity (for lack of a better word) of athletic and other activities for high school students. High school athletics used to mean the big three, football, basketball and baseball. Now those three sports have been supplanted by many others that decrease the interest and participation in the big three. Students are not as vested in the three sports as they had been in the past. And that's just sports. The variety of other extra-curricular activities is much, much greater than ones were available to me back in pre-historic times.
I met a freshman at a student send off this past summer that never attended a football game in high school because he played soccer. He had no idea of the history of football at Notre Dame.