If you think any of those three groups aren’t primarily about helping themselves, you haven’t been paying attention. Usually helping themselves to power, but also material wealth. Or reacting to current privilege being perceived as under threat.
Your whole thesis depends on one unstated assumption. It’s the idea that most people are basically good, that most aren’t inherently selfish. That it’s just “shortsightedness” that causes people not to cooperate.
Well, I don’t believe that’s the case. I believe most people are not good in that way. Not even neutral - most people are a little bad. Selfish as well as bigoted and hateful. And even more are either stupid or ignorant. Evil and dumb is a terrible combination.