Piketty always has insightful commentary on the topic and I'll definitely be checking out this book. I think we'll come to recognize that R > G is an important influencer for social stability and long term prosperity.

That said, I do wonder if we're looking at inequality (or more specifically hierarchy) through the wrong lens. It seems like almost all independent societies naturally develop some sort of hierarchy (chief, priest, leader) without any outside influence. To me that points to some underlying natural law or at least a biologically-influenced tendency that higher level social constructs will be ineffective at changing.