I don’t know if it’s helpful to frame this as them being fooled either though, they are getting exactly what they want. Racialization emerged from settler-colonialism specifically for its ability to naturalize the subordination of groups within a hierarchy organized around capitalist imperatives of profit and infinite growth. White supremacy is a whole-hearted subscription to that hierarchy and its maintenance. Our system is racist already and has been the entire time. Even though white people are not all billionaires, they understand that being white guarantees them privilege over other groups in society and that typically translates to a lifetime of material security and even luxury. Opposition toward an owning class fundamentally depends on condemnation of stratification and hierarchy as those are the underlying mechanisms that make wealth accumulation possible. When white supremacists – this includes white people who do not describe themselves as Nazis but nonetheless subscribe to our system as it is – align with the interests of capital, they are communicating that they will defend the hierarchy they benefit from before they will challenge it. Even if it appears as though they are duped because of the disparate material reality they experience compared to billionaires, or any owning class, that they can entertain the fantasy of rising in the hierarchy is itself only made possible through a construction of the world where some people are just born with the right to enjoy life. They know that whiteness gives them that and they are rewarded with the luxurious precarity of middle-class life. I don’t think you can understand why people make these sorts of decisions with an individualist analytical framework like psychology, it is systemic.