It is about upbringing (I hesitate to use the word breeding) not money.
There are enough classic novels around describing the turmoils of the "genteel poor".
The differences will never disappear. The way we deal with those differences is what counts.
I have a dear friend with enough money to float a ship. She worked for it, coming from extreme poverty. Her roots are completely obvious and she has intentionally kept many of the habits and idioms which formed her, as she couldn't care less where others place her on a 'scale' and is proud of her achievements.
Her boys, on the other hand, are absolute snobs, and middle class every step of the way...expensive middle class nannies, private English boarding school education, education, hobnobbing with a few minor titles, old boy route into very nice careers, and very firmly of the "not quite our type" brigade.
My mother tells me that she thinks they they only invite her to social events because she can probably still buy and sell them, and can be passed off as quaint and idiosyncratic.
It is noteworthy that she is American, and this has played out in that supposedly classless society. She will always be considered "new rich" not "well bred"
We don't own the rights to class distinction. We are just more truthful about it.