Frank Knight said profit only exists because of the risk you can't measure

In 1921, economist Frank Knight argued that true 'risk' -- like a known dice roll -- can be insured away, but genuine 'uncertainty,' where the odds themselves are unknown, can't be. He claimed entrepreneurial profit is specifically the reward for bearing that unmeasurable uncertainty, a distinction economists still call Knightian uncertainty.

— Frank H. Knight, Risk, Uncertainty, and Profit — Houghton Mifflin, 1921