By luck and status. Right place right time. They have some experience, and they just so happen to know X, Y, Z (probably because their dad knew X-1, Y-1, Z-1 and so on) so they get in. Maybe they went to harvard or something.
What opportunity manifests at the right place and right time? What's an example of this? And if it's based on knowledge and experience and an acquirable credential, then we're right back to square 1.
Its complex, because even if something is unattainable by knowledge and experience that DOES NOT mean its equal opportunity.
Simply being born into a richer family means you're significantly more likely to earn a higher education. Simply being born into a white family means you're more likely to finish high school.
And this is leaving out connections. If you know the people hiring, you have a better chance of getting hired. High-status people know other high-status people. If your family is high-status you're at a HUGE advantage.
That doesn't mean the opportunity "manifested" for you. But, it does mean your likelihood of obtaining said opportunity went higher.
I mean, when you look at the proportion of CEO's who are white, tall men as opposed to the regular population you notice that. It's an open secret. Some say its coincidence. I don't think anyone really believes that.