And even if you can get over the fact that you're only strapped to vines, the land divers pretty much hit the ground after every jump. It seems like something would break, eventually. National Geographic writes:
Bungee jumping officially began in 1979, but men on Pentecost Island in the South Pacific have practiced nagol, or land diving, for centuries. In a ritual full of symbolism and spirituality, men dive from a wooden tower up to 100 feet high with nothing but vines attached to their ankles.
It's definitely nicer to see the point of view of a tribal land diver on video than it is to make the leap yourself.