Like if you by groceries, rent an apartment, have a bus pass, qualify for Medicare, and you have a Netflix account or get fast food (discretionary spending), then you seem to be middle class by this definition. Is that right? Maybe Medicare bumps you out. But ok, you can get the cheapest marketplace plan.

I mean, to be below middle class by this definition your expenses have to exactly match your revenue, or you are living beyond your means. So other than some tiny slice (in some perimeter vs area sense) of the populace, being working class seems to be definitionally unsustainable.