Bottom chart is missing compound interest. This makes the birth lottery so unbalanced in the first place.
The focus on the hyperrich forgets that there is also inequality between someone who owns a house/has some hundreds k€ invested and the rest of the population. Which will then get compounded in the next generation.
Finally, I do not think it is even close to half/half. In order to be in the position to exploit the working class you more than likely where born rich first.
the trick is to combine all your uncertainty sources together. So in the worst case your numbers still have as much entropy as if you did not have the external source. And even if somebody else knows those numbers they do not know the actual numbers you are using. Of course that raises the question: if your other entropy source is good enough that you are happy in your worst case what is the benefit from some extra source of entropy? So i have argued myself into agreeing with you :) crypto is not a good use case for such a service. The wall of lavalamps mentioned above is a better solution.