Most people that "drop out" of college actually were flunking out. Yes there are all kinds of reasons people leave college but those that quit usually do it because they are failing. And you really don't get to the difficult classes until later in your degree so if you flunk out in year one, you never saw the "hard" 400 level classes.

And yes, there are easy majors and there there are difficult majors that "weed out" those that can't pass the challenging classes.

Nothing personal, some folks are talented at math or problem solving or science and others are very skillful with motors, using their hands etc.

It takes all kinds in this world. The real talent is to know what skill set you have and would enjoy pursuing rather than wasting time and money on something else.