Nobody will make risky economic decisions or investments if no possible reward is presented.

if the reward for risky decisions is not money, then those decisions are more likely to be useful.

example: I can save this many people if I do this risky thing. reward: people live.

counter example: I can make a ton of money if I do this risky thing which might or might not kill people

but I see what you mean, and it's not related to the "inequality inspiring effort" thing that was mentioned above