I assume that Uber is not competing with black market interest in bugs, rather they are competing against interest in other bug bounty programs. The number of

I assume that Uber is not competing with black market interest in bugs, rather they are competing against interest in other bug bounty programs. The number of people who earnestly compare rates between bounty programs and black market buyers before deciding who to inform must be vanishingly small. However, the number of people who compare bounty rewards before deciding who to test against is likely much higher.