The advantage of the larger school in my experience, is that its like going to a dozen small schools at once. Plenty of people I know where able to transfer from one good program to another in a completely opposite field once they learned what they actually liked (usually quite different than what you imagined as a highscooler especially if your parents have no concept of the field), because the school was large enough to offer so many good options and departments with a lot of interesting faculty. The class sizes are the same between big and small schools anyhow for the most part, but you also have an easier time scheduling classes (and taking certain ones “out of season” if need be) at the larger school. It scales horizontally rather than vertically as your student body increases, big schools have the pockets to hire more faculty and support more taships than smaller schools.