And Upper class is the aristocracy, not the wealthy people. Like a broke person with a noble title is still in the upper class. And below that is the ruling class. So politicians and clergy. And middle class is wealthy people without titles.
In America the class system shifted since they don’t have a royal family as head of state. And thus lots of working class people think they are middle class only because they have a job and aren’t living in destitute.
Aren’t you just describe two difrent Modells? I mean both have Thier own use case. But yeah living from paycheck to paycheck dose not sound like middle class
System ≠ model For example there are difrent ecosystems (dessert, jungle, River, lakes) and there are different models to describe an Ecosystem (food-networks, statistical models, energy pyramids) And this distinction exsist in every filed of since from physics over Biology to social studies