I think it's better to segment in terms of percentiles.

Biles, Musk, and Phelps are in the top 1% of their professions. They stand out a lot.

The folks in the top 10% are often way more comparable and differences between them are negligible. It takes something special/extra to stand out in this crowd, and for many of them, it's not about working any harder to make it to the top 1%.

It takes a lot of luck/opportunity, and extraordinary natural talent to become part of this 1% group. Which is why their success is not easy to replicate. And it can come from anywhere. None of these people had parents or families in the top 10% of the same profession.