Nah, there is definitely a truth to this. I grew up in a working class family who moved into a wealthier region at some point and I would never trade places with people who grew up wealthy. Pretty much all wealthy people are constantly unhappy, are obsessed with control to the point where they alienate their families, they are constantly scared of losing their control, status and wealth, constantly paranoid towards everything and everyone and often engage in self-destructive behaviour.
Of course, not having enough money sucks, it generates stress and restricts autonomy. But a similar thing happens at a certain level of wealth.
Unfortunately, being firmly from a working class family, I can guarantee you that we plebs struggle with the exact same things + actual poverty (not being able to go to a doctor,…).
I wish I could say we’re magically happy for every crumb thrown our way, but we all realize we are scrawny mice at best while the world is ruled by cats.