Let's Talk About RPG Worldbuilding

[Yora]

The realistic approach would be that the privileged people assume the underprivileged ones are envious and want to take away their privilege, so they have to make sure to keep them down and not do anything about it.
Also, when it's convenient to blame someone for problems and not wanting to make the effort to change it or take responsibility, the underprivileged people will get blamed because they can't fight back.