We have been devouring each other for ages now. Entire cultures have vanished, destroyed by more powerful members of the same species. The entire history of our species has been on violent conflict where a stronger group removes a weaker group, only to be removed later by another group that emerges stronger. Previously it was racial, clan-based violence. Now it's economic servitude where a perpetually unfortunate lower class keeps on greasing the wheels of industry with sweat and blood. The rich stay rich, the poor stay poor.
We are not benevolent or kind creatures. We are programmed to survive. As long as the poor live, they will rarely question the rationality behind the inequality that keeps them poor.