As an MIT alum, I don't see a ton of value in competing over whose classes were the hardest. I've met super impressive people from everywhere from community colleges to Rhodes scholars and do not subscribe to the idea that MIT alums are uniquely good.

But having taken some physics and math courses at multiple universities MITs went much deeper in a shorter period of time. This isn't necessarily reflected in the syllabus because the topics may be the same but the devil is in the details.

MIT had absolutely fantastic problem sets that took me 10+ hours a week per class to finish and were rarely changed from year to year. This is because they've been tuned over so long that whether you get the answer correct is almost besides the point, the useful part for learning was the process of banging your head against them. This was true to an extent at other universities I've been at but usually the expected proficiency required to excel in a course was not quite so severe.

I ended up getting a PhD (in materials science), spent many hours working as hard as I could in lots of classes, and despite honestly knowing my stuff quite well I never got an A in an undergraduate physics course at MIT. Those were only gotten by the students who were obviously frighteningly talented, often with research experience in the course material already. Don't take that as sour grapes or anything, I am super proud of my B's in these courses. But MIT grades harshly, which may be part of why it's "harder".

Most MIT students stop caring about grades freshman year. Most MIT students interact with one another in class as fellow masochists struggling together against a common foe (learning the material) rather than competing against one another for grades. This is what I would personally call the weirdest and most advantageous aspect of MIT versus Ivy Leagues, but I actually think state schools are awesome at this too.

I'd have put that environment on the list of lessons way before any of the ones on there. Learning the value of close collaboration with people, regardless of whether you may think (probably wrongly anyway) that they're "better" or "worse" than you. Learning that when it comes to the real world, on a team you're all up against a way bigger opponent than each other, you're up against the laws of nature. And that success against that opponent is far more satisfying than any grade.