> and you observe other students putting similar amounts of effort, but obtaining much better results, understanding things more quickly and getting better ideas, you should probably just drop out

Sorry, but that would be just dumb. The starting point matter awful lot. I remember multiple things that were super difficult to me and I was slow, until I learned some missing piece and it clicked. Then I became good.

Initial struggle does not mean anything. There is such a thing as talent, but fixing your preexisting knowledge and calculating exercises will move you up into "it is not an effort to learn further" category awful often.