Are equivalent classes more difficult at high-end colleges compared to StateU?

If the difficulty was the same, why do we see so many threads about kids wanting to take things like O-chem at home over the summer? And why do so many of the posters who advise the pre-med kids on this board keep telling them to go to a college where they won’t be in over their heads?

All classes can be taught at varying levels. For English, how are the papers graded? And are there any papers? For STEM subjects, are kids tested on what they learned in class, or are the tests full of “push” or “stretch” problems that they have never seen before (but if they work hard they can come to the right solution).