I think there are two types of properties: intrinsic and extrinsic. Your intelligence is intrinsic. It’s internal to you and is highly correlated with your genetics. Your success in life is extrinsic. It’s based on factors outside of you, like the circumstances of your family, etc.

So, no, I’m not saying success is purely genetic. But, I also think there is a strong genetic component to one’s intrinsic ability and so not everyone can reach the top even if they work really hard.