How important is parental/generational wealth in determining people's success?

There are people who are born into powerful, wealthy families and become wealthy because of it, there are people who are born into wealth and spiral into poverty, there are people who are born into wealth but whose wealth is almost entirely the result of their own effort and success.

There are also those who are born into poverty and remain in poverty, and those that are born into poverty and become wealthy.

I imagine how much you think generational wealth affects personal success depends on the level of generational wealth you have experienced personally. As someone born into relative poverty, it's very hard to imagine how someone born with a "free ticket" could fuck it up. But there are plenty of people who are born to wealth and don't convert that into lasting success. My dad is one of them. It's also hard to imagine how someone born into poverty can become wealthy, but there's plenty of people who have done just that.

With such a wide spectrum of outcomes across all states of generational wealth (or lack thereof), how important is generational wealth really in predicting success?