This could also be a story of technological progress. A thought experiment - imagine you, an archaeologist, recovered the remains of our civilization, from roughly 1925 to 2025, but the only surviving artifact was televisions. You know that televisions are valuable - initially only wealthy families had them - so you used them as a proxy for riches and plotted the Gini coefficient using just the size, quality, resolution, color depth, etc. You could conclude that our society became less unequal over that period, because you miss that technology dramatically compressed the distribution of this resource and that household wealth was freed up to put to other purposes.