[groby_b]

Yes, absolutely. Any economy is ultimately about efficient resource allocation.

The question is then, how do you measure efficiency. Proponents of a more equal world argue that the current extreme imbalance is only "efficient" for a very small subset of the population, and likely inefficient both for the vast majority, and for long-term success of societies.

The long-term question is basically a result of economies being feedback loops - if benefits accrue inequally, and capital results in opportunities, any system that doesn't have some negative feedback loops ultimately will amplify the inequality more and more.

In extremis, that means one person with all the resources. I'd argue that this is an outcome that probably nobody wants.

And in the context of OP: unless the total cake grows faster than the inequality, this holds true for non-zero-sum games, too.

The world has experienced tremendous growth in the past. It doesn't right now (and it can't sustainably continue growth in many areas), so the question is, what feedback loops do we want in place.