Everyone's life is a mix of skill and luck, so to discredit skill, you would need to quantify the luck. An easy example is a lottery winner, a hard example is a Bezos. Any investor with the foresight to see what Bezos could do with grans money, would jump past her in line and give him triple.
I don't think that really matters? The fact that they even had that shot at all is such an incredible opportunity above people whose family simply cannot afford to even try
There are far far more stories of investors giving nascent broke startups money than families.