If you were to take a random room of people. Reset all of their incomes to square one. In a few years the same people that were rich to start would emerge "rich" again.
Some people are willing to be disciplined and motivated to change. While others talk without the walk.
Donald Trump is rich because his dad left him an inheritance. His businesses were fraught with turmoil. If he just kept the money in an index fund, he would be richer than he was today.
So reset everything to square one, and there's one person who's not going to make it on their wits.
Need more examples? How about Bill Gates? No doubt, a very smart guy. But he would not be where he is today without that fateful meeting with IBM, where MS negotiated providing DOS for the PC. How did he get that meeting? His mom worked for the United Way, and knew IBM's CEO.
Then consider everything else that led to that day. He grew up in a fairly well-off family which could afford to send him to MIT. He was in the right place at the right time when Gary Killdall dropped the ball. He had the benefit of excellent timing, as the window for establishing OS dominance on the PC was very small. I'm sure Gates would even tell you - his success is, in large part, a product of luck.
What I'm saying is, to become rich, it's not enough to be talented. You have to get the right opportunities and seize those opportunities when they come to you. In my experience, there are more people with talent then there are opportunities. So that random room of people is always going to turn out different.
Some people are willing to be disciplined and motivated to change. While others talk without the walk.