I read the question If we assume that protons don't decay, then will all matter ultimately decay into Iron-56 or into nickel-62?, but I have a different question concerning the decay that has nothing to do with quantum tunneling.
My question is this: If $^{62}\rm Ni$ has a higher binding energy than $^{56}\rm Fe$, why wouldn't all of the heaviest elements (even those man-made) decay into $^{62}\rm Ni$?