I understand what you're trying to say, and as an anti-capitalist I want to agree with your sentiment. But the truth of the matter is, statistically (just google it) most multimillionaires and billionaires living today acheived their wealth through inheritance. They were born rich. Generational wealth inheritance makes up an overwhelming majority of the richest 1%'s source of income. I don't think being born rich inherently makes someone heartless/ruthless or whatever.
You are correct that the process is not automatic or inherent. However there are substantial pressures on the psychology of nepo babies by their environment that make developing into terrible people much more likely, and judging by the behaviour of those who come from inherited wealth, I would speculate that statistically not many of them manage to escape those brain worms.
Hell, quite possibly the only moral thing you could do as a child of astronomical wealth once you have autonomy is to divest yourself of that money, pour it into worthy causes while still retaining enough money to be more than comfortable for the rest of your life, and likely the lives of your descendants. But a lot of the wealthy don't even bother with the cynical PR level of charity, much less something actually meaningful or impactful.
Continuing to sit atop a pile of stolen jewels does not make a person moral just because they didn't personally steal them, just ask the British royal family.