I don't disagree, but better doesn't make up for unfairness.
Inequality isn't an act of nature. No volcano or hurricane is disrupting lives. The source is human, a system we built, the society we live in. If we can't change the system that binds us, then it doesn't deserve us.
The core conceit is, "When I win, it's merit. When you lose, it's fair."
I don't disagree with most of what you're saying either, but I don't see it's relevance to what GP is claiming. Was society more fair than it is now for the last few millennia of higher birth rates?
Conscription, poverty, illiteracy, I mean wow.
By almost every conceivable metric, the world is getting better.