I would say that's on the wrong track and that "hard" is the wrong term for what reverse math (RM) tells you about problems. RM studies what axioms you need to prove a given theorem, but it's more like showing that "to pound in a nail of size X you need a hammer of size Y and a smaller hammer just can't do it", than saying pounding in the nail is difficult or complicated. Once you have the big enough hammer, pounding the nail can be very simple.