Exactly right! The reason that politicians talk about there being 3 classes is that 3 is a nice, round number that just sounds nice, and also it allows everyone to pretend that they're middle class.

There's a collosal social difference between living paycheck to paycheck without any disposable income, thus depending on retaining your job to be able to keep a roof over your head, and being economically self-sufficient to the point where you are free to take multiple holidays throughout the year and even be free to quit your job and live off your savings through long stretches of time.

Middle class does exist, and it's existence is rather obvious. Trying to conflate middle class with low class or poverty makes no sense at all, because the plight of a low class worker has absolutely nothing in common to the problems and challenges faced by middle class workers.

The rights you have as a member of the 'middle class' have much more in common with the lower class than the highest class.

It is also a lot easier to move from middle class to poverty, than it is to fall from the upper class.

Yes, it feels like there is a 'colossal difference', but it's not nearly as big as the difference between middle class and the ultra-wealthy.