Define fair. Is it fair that Neymar's feet are so much more coordinated than mine? Or that he worked really hard, risked his life, gave up bad foods and free time to dedicate himself to something he loved, then became successful? Is it fait that his parents passed on their genetic advantages to him?
Is fairness really the issue? Is it economics or government that creates wealth disparity? Is it the rules and laws that skew the playing field towards those with money? Is it fair that some people dedicate decades of their life to building wealth and are then forced to share that wealth with others? Is it fair that some people dedicate decades of their life to serving wealthy people and are then dismissed without compensation? A gun can kill a rich man as easily as a poor man, but justice rarely gets served on the innocent welfare mom killed by a stray bullet.
Fair is hard to define. Maybe capitalism is fair enough, but humans just suck.