If you ever read The Millionaire Next Door you'll read a lot of very similar stories about small business entrepeneurs who had a combination of drive and opportunity to succeed, but most of all (at least emphasized by the book) sound financial principles that kept them from losing it all once they made it.
I've only spent time with one person like that - a distant uncle I acquired by marrying into my wife's family and he was exactly as described in the book. He had more money than he ever needed, but he still worked and tended to his business, he never moved out of his starter home, never bought flashy cars or did anything to display his wealth. He wasn't miserly but he just didn't see the need to waste money.
IMO, do you (not you you but theoretical "you") want a lot of money because you want to use it for something, or just to have a lot of money? The way I see it, there is no promise of tomorrow. This doesn't mean don't plan for tomorrow, but e.g. an ex of mine had grandparents who would live super frugally (up to and including using McDonalds napkins at their house and "stocking up" every time they went to get their free senior coffee...they also had exclusively sauce packets). They were super proud of how they were [single] millionaires, having saved almost every penny throughout both of their normal office job careers. They lived like they were poor for their whole lives to attain a number in their bank account. They had no plan for anything to actually do with their money, they just really wanted to be millionaires. I see absolutely zero point in this.
Obviously, it's their money and theirs to do with what they want, but if all you can think to do with a large sum of money is keep it in the bank or in stocks / bonds with no actual purpose in mind (starting a business or non-profit, early retirement, world travel, owning a home, owning a helicopter, donating it, a few years of hospice care for someone in your family, whatever) it just strikes me as super boring and a waste. I don't actually see how people can work so hard to simply attain a certain number on their bank statement when that is the sole goal. To me, that is a total misunderstanding of what money is, and I feel somewhat bad for people who do this.
I've only spent time with one person like that - a distant uncle I acquired by marrying into my wife's family and he was exactly as described in the book. He had more money than he ever needed, but he still worked and tended to his business, he never moved out of his starter home, never bought flashy cars or did anything to display his wealth. He wasn't miserly but he just didn't see the need to waste money.