The current situation of the market and number of scam campaigns affect bounty campaigns quite a lot. Even in campaigns which are successful, the reward is usually not satisfactory. Also, the number of successful projects has decreased significantly due to the market. In this case, it reduced the number of successful bounty campaigns too much. And i think unfortunately this situation will continue in bounty campaigns until the market improves.
It is quite indeed that it is so hard to find a very reliable bounty that we can join, I dont know any bounty that I will invest my time and effort. It is affected by the current state of bitcoin, bitcoin is uncertain also that is why most of the bounties before failed to have a good and huge sale because of that. Since halving will happen I hope that good bounties will come out.