The question of whether the bronzes should be returned to Benin is a matter of ideal morality and practicality. Let us ignore where money has travelled as a result of these bronzes being moved. On one hand, these spoils of war should be returned to their country because they are items of heritage and culture, and the people of Benin deserve to grow up around items belonging to their culture and past. On the other hand, Benin does not have the resources necessary to manage these artifacts as well as the other countries do.
An impractical solution would be for the countries holding these bronzes to build facilities to hold and showcase these bronzes in their country of origin, as well as to provide and teach the skills needed to maintain these artifacts. Of course, no country would approve of this because there would be nothing to be visibly gained from this action. It does, however, solve the problems of not being in their country of origin and the maintenance of these artifacts.