I don’t think a hs kid can constructively analyze the difference. But the strengths of peers at X Univ can allow a higher depth and breadth of teaching and expectations (tests, projects) than at Z Uni. The bar for an A grade can be higher, based on this. If peers come in with the highest preparation, you may not be comfortable with the pace and rigor they’re ready for. It depends.
But better knowledge after graduating from X? Not necessarily. There are fabulous CS grads from many different levels of college rankings.