Yes there is a working class, yes there is a middle class. You can 4 classes or 6 classes and they will all have needs. But it doesn't do anyone any favors to keep pretending that there are not two distinct groups in the world: those who produce and those who siphon off their productivity for themselves. There is wealth inequality amongst the productive class but they are all using their labor to general value. Service workers and doctors may have wildly different incomes on a micro level, but they are both producing value for society. Hell, even some politicians are producing value when they actually govern and enhance productivity.
These people are distinct from an entire parasite class of individuals born into wealth, whose entire purpose is to extract as much value from the labor of thriving productive part of society and take all that value away from productive society. The wealth inequality between this parasite class and the productive class dwarfs any marginal differences amongst the productive class. They use this wealth to manipulate society and the productive class to further enhance their ability to extract wealth. They will take as much as they are able while trying to keep the host alive. Sometimes they fail and kill the host.
We need to defend ourselves against these leaches and the entire paradigm of a three class system is a manipulation to suggest there is some sort of even distribution of wealth. It's an outdated model and actively harmful.
Recognizing and using accurate terms to describe the state of wealth is conducive to realigning popular perception of wealth distribution. These parasites have no interest in enhancing the lives of productive society and no conscience and not even a good sense of self preservation. They are not the same as you and I, any of you. Yes you can use the same logic that a small business owner does the same but it's not true. Even the shrewdest small business owners are generating real value. I'm not talking about them, the parasite class contributes effectively nothing compared to what they extract.
I'm not an economist or an expert, I just pay attention and I see that it's all a lie. We have hair worms in our societal brain and it is causing our productive society to drown itself in a pool.