I agree with a lot of what you say, but imho it's problematic to consider class a characteristic that's easily mutable. When social mobility is near non-existe

I agree with a lot of what you say, but imho it's problematic to consider class a characteristic that's easily mutable. When social mobility is near non-existent, then class has effectively become it's very own immutable characteristic. People can be born into wealth and poverty just as much as they can be born with colored skin. The "American dream" is the anti-thesis to that, stipulating that everybody can elevate themselves out of their lower-class if they just pull those bootstraps hard enough. But how realistic is that actually nowadays, particularly to elevate larger parts of the population?