Capitalism in its current form is indeed extremely greedy, but that's only because of the corporations. Creating a capitalistic society without morales will lead to the definite ruin of the planet by greed. Religion in some shape or form, even though it can tend to be a corrupt structure, oftentimes acts as a safety net for those whom are impoverished.
That being said, a socialist/collectivist type society could indeed succeed if there is enough social cohesion in a particular group, it would not work on the basis of nations, the closest you can get is a Social Democracy like Norway or Sweden.