My take is that a single trait - that is, capacity for delayed gratification - is responsible for the majority of wealth accumulated and probably majority of individuals who get rich in life. It doesn't take much else really. As long as you are not severely disadvantaged (have congenital disabilities, very low IQ etc), and live in a more or less stable country (no civil wars every 20 years), and you are good at delayed gratification, you will almost inevitably make it. It's only terribly bad luck (cancer, accidents, crime) that could stop you.

Most people think this is not the case only because media is not telling about it, because there is little to tell about really. Except extreme cases like https://www.cnbc.com/2016/08/29/janitor-secretly-amassed-an-...