I think that it rarely works in Western culture, but that there is nothing intrinsically wrong with it. It worked well in traditional Tibet, for instance, and prevented problems of land ownership that were a major cause of cultural troubles in Europe for centuries.
People have endless ways of relating and trying to relate well. I suggest we find what works for ourselves and let others do what they will do.
Given how poorly we're doing with monogamy, let's not criticize what others might do. At the same time, given how poor we're doing relating as couples, are we really ready for more complicated intimate relationships?
I've seen one case of successful, happy polygamy with the people raising very healthy children in the US. Of course, it is essential to keep it quiet due to prejudice. There may be many more.