You don't disprove a trend by citing a counter example.
It
is all about parents. But the genes they gift you are more relevant to the average person than the money. There were multiple occasions throughout history where rich and powerful families were disowned and yet, 2-3 generations later, their children were once again among the elites of society. The plantation owners after the slaves got freed, in China and I think a few more Asian countries when the communists took over.
The west pretends like it's not a functional meritocracy because people and people of different races in particular don't achieve similar aka fair outcomes. But that is down to the true root cause of inequality, genetic inequality. Intelligence, diligence, conscientiousness, ambition. All of those are partially down to your genetics and all of those play a big role in how far you can climb the societal ladder, both in terms of status and money.
A few quotes from this paper:
https://gwern.net/doc/iq/ses/2022-marks.pdf
And then just the entire
Discussion part. The first paragraph gives a good idea:
This isn't to say that the top <1% don't profit massively from the wealth their parents gift them. But that's not the majority of the population. In general, rich people not only have money to bequeath, they also have genes they pass on to their children. And, on average, those are the real driver of inequality, be it in terms of money, intelligence or looks. That idea is pretty much the core of the blackpill.