It's never because you're very passionate. Passion has basically no correlation with financial success. Millions of passionate artists, musicians, writers, and all of them broke as can be, most working shit jobs to pay the bills wishing they could just be passionate and make money from that. Passion is bullshit.
The real path to financial success is a combination of: being born to parents with the means and motivation to see you well education; being born lucky enough to be a little bit clever; being lucky to pick a career that makes a lot of money, often only by ignoring idiots who say 'follow your passion; putting in a lot of hard work to get good at something that is in-demand.
Or the usual answer: just being born wealthy and wouldn't-you-know-it you wound up wealthy too.
Have you got any evidence for this? I would expect that passion correlates with hard work, and hard work seems to be necessary for success. I agree that many artists are passionate, but surely people can also be passionate about doing things like writing software or other activities that are valued highly in the market.
We live in a culture that wishes passion lead to success. It's what we're taught as children here. It's what we want to be true.
And yet I find no strong evidence anywhere supporting the assertion that it does; just people claiming that it's up to those who doubt to disprove it.
Passion is a fairy tale adults tell each other because it's nicer than the reality that dumb luck and being born wealthy are the only real chances we have.
And those who were lucky or born on third base love to tell everyone it was because they were just so darned passionate.