Americans and others in the advanced world are wealthy beyond the wildest imaginings of almost all of the rest of the world's people except for Saudi Arabian princes and African dictators. We own homes and cars. We eat more than we need to and see doctors. We have nice clothes and endless electronic stuff. These are beyond the dreams of Third-World people.
Law accounts for the difference.
Advanced societies unlock resources and put them to use. Third-World countries do not. Often, Third-World land titles and laws establishing and protecting them don't exist. By contrast, beginning late in the 11th century, common law focused on land. Tribal rules control.