A financially advantaged family can provide opportunities such as better education, private tutoring, overseas experiences, or attending prestigious schools. This can be a significant advantage on the path to leadership positions. Wealthy or well-connected families can provide their children with a strong social network.
Leadership positions in business or politics are often supported by connections. In short, a family's financial background and education are all major factors.
This generally occurs because when we have a financially secure family, they can help us achieve success. The pattern can vary, as you mentioned or conversely, they can provide sufficient capital to support success. Being born into a financially secure family can provide far greater advantages than being born into a poor family. This isn't about being ungrateful, but rathe opportunities can be much easier when we're in a more secure family.
If we come from a secure family power can be attained or in other words bought. I've seen leaders in my country generally come from secure families, and they also come from families that have previously held power. Success that is built from scratch may exist but it is very difficult even though we don't need to give up to get it.