I'm starting my bounty career in 2016. I earned huge profits from did bounties in 2016 because in 2016 there are few participations in bounties. So receiving the reward is big. Personally, I earned 27ETH in 2016 from bounties. I think I earned it within one 11 months. But at this time it very difficult to do because now all bounties have too many participations. So very hard to take good profits. But I really love the bounty campaigns.
I think in the near future the number of participants in the bounty will significantly decrease, because the whole market is now in a very strong decline. People usually need quick results, they are not ready to wait.