you are talking about one of the most successful businessmen and billionaires.
Not true!
Much has been written about it. Here's a piece from 2021 from Forbes - headline: "It's Official: Trump Would Be Richer If He Had Just Invested His Inheritance Into The S&P 500".
Source: forbes.com/sites/danalexander/2021/10/11/its-official-trump-would-be-richer-if-he-had-just-invested-his-inheritance-into-the-sp500/
In total, Fred Trump willed to his children an inheritance of $1 billion, which was an enormous sum throughout the 1980s and 1990s when the inheritance was being distributed.
In theory, his children owed a tax bill of $550M on that amount, but in the event paid only $52.2M or approximately 5%. This is why Maryanne Trump Barry (POTUS' elder sister) was forced to resign as a federal judge in 2019, because this earlier malfeasance with the inheritance was starting to surface.
Out of the total, Donald received the lion's share, or $413M. This, despite him writing in his books and saying in his speeches - that he built everything off of a "small" $1M loan from his dad.
Even $1 million is not a small loan, whether in the 1980s or today. But $413 million is on another order.
If Trump just gave that sum to professional managers, he would be substantially wealthier now. He could spend his entire time banging models, sailing in the Caribbean, and doing cocaine - and still he would have done better than through his active business efforts.
He is a singularly unsuccessful businessman.
What he is - is a very successful entertainer.