Almost everywhere, a tribal chief says what goes. If the Tareras move to town for a better job, the head man can take the land and turn it over to someone else, perhaps a buddy. No bank will touch it. The family's customary lands are sliced up as children come along. The more slices the smaller, often to the point of uselessness.
Capital remains locked up for generations.
In developed countries, the legal system protects not only ownership but transactions. That means, for example, that you can contract for construction. In Mtandire, the Tareras built their house from the ground up. If the customer can't prove ownership, no contractor will work. Moreover, in the Third World, law doesn't provide a ready method of converting from customary to formal status.