I think that it's an easy thing to trace... Who does what and why do they do it? Why are some successful while others fail? Well, it's because some peoples purpose is stronger than their demons. This allows them to never give in to the desire to sell out or quit on their soul's quest.
But why are people successful longterm? Because they have an ongoing purpose to strive for. Many people attain success but then lose it quickly, why? Because they don't understand success. It's not about doing something for yourself, it's about having a meaningful purpose to achieve. A legacy to work towards if you will... A truly successful person will be successful as long as they are pursuing their purpose... That's because they define their success internally.
You are probably thinking. Wait, isn't Kim Kardashian successful? What's her purpose... Well, I can't comment on someone like that, but you can never tell if a person is actually successful without knowing what's going on in their heads. I would say there are many people who appear successful, but who are actually quite miserable... Why? Because their soul is screaming inside of them to live their truth. When you are wrapped up in the ego of life, it's hard to live a truly meaningful, purpose-driven life.
The greatness of life lives in a place where people don't anticipate. It is in the silence, it is in the stillness. It is in the small joys, the love given and received. This is a success. Money and other things are fun pleasantries of earthly life... But they hardly define success. Success is waking up every day knowing that you can go and fulfil your highest purpose.