It's an example where greater welfare may be derived from less overall wealth, if a) the marginal benefit of more wealth per member diminishes with each additio

It's an example where greater welfare may be derived from less overall wealth, if a) the marginal benefit of more wealth per member diminishes with each additional unit, generally, and b) the distribution between members improves, such that more members are in the steep part of the slope. Proponents of capitalism usually point to (a) not always being true. That is, at some point, and under the right social conditions, the marginal benefit per unit picks up again, when instances of per-member wealth is great enough to finance capital-intensive production.