[s_m_t]

Because the idea of class interest being split along easy to understand lines like billionaires versus everyone else or rich people versus poor people is a fallacy. In the real world your economic interest relies more on exactly how you make your money, in what industry, in what region, what your assets are, etc, etc. A teacher in California might have close economic interests with billionaire group X and a truck driver in Wyoming might have close economic interests in line with billionaire group Y.

Everything else is just propaganda to try and give a compelling narrative to these unintuitive groups. Because what we are actually talking about is essentially a classification problem in highly multi-dimensional space there really isn't a coherent narrative. The only way the propaganda narratives make sense to you is if you have shut down your critical thinking skills. Being confused means you aren't a brainwashed partisan.