There's a lot more to it than wealth and income.
There are cultural differences, obvious physical differences, food preferences, and rituals not held in common.
Those taught to fear outsiders will always show prejudice to persons with unfamiliar looks, language, and lifestyle components.
Too many here think economics define all aspects of life. They are important, but not all-inclusive or omnipotent in what they can and cannot effect.
Granted, people are happier when they can meet their needs and have a little left for luxury or indulgences. And when people are happy, they're less apt to pick up guns and shoot at target groups or harbor much in the way of hatred.
Still, casual dismissals of race and gender prop up the same White Patriarchal System that set up the castes of privilege and power in the first place.
Eradicating merely the economic component doesn't change the rest of the calculus.