> We could evolve our economic systems to redistribute obscene wealth and build a more egalitarian society.
There is not enough of what everyone wants. There's no way to get it. Let's take a trivial example. There are a number of companies out there making smartphones. What if everyone wanted iPhones? There may be enough iPhones out there to give one to everyone in, say, New York City. There is not enough, and there will never be enough iPhones to give to everyone in the entire world.
If you're just talking about money, then that's even worse. If you redistributed all the wealth in the entire world among 7 billion people, every person in the whole world would get a check for the princely sum of $8.57. (Obtained by dividing the entire world's money supply, found on Google, by 7 billion, roughly how many people there are in the world right now) Meanwhile every single organization, every single company doing anything useful for the world has been completely decapitalized.
There simply isn't enough wealth in the world. And making everyone equal is the best way I can think of to ensure that no one will ever have the ability to make more wealth. Like it or not, we're stuck with inequality for the foreseeable future. Either people are going to be unequal in purchasing power terms, or in the fact that production capacities for all possible luxuries people might want are not and will never be world-scale. You can't give everyone on the planet a NYC penthouse. And until you do, people will complain about inequality. We need another way of thinking about the problems of the world than that some people have lots and lots of things that other people don't.