something I have come to realize of late about the bounty is make proper research about a campaign before going into it. also, dispose your mind to the fact that some campaigns will not pay much because of how much is assigned to the project and the number of participants involved in the project. also, we should be aware of the level of a scam project that doesn't pay. not getting paid for a campaign can be disappointing but we can comfort ourselves with what we have learned so far and not give up, because of a failed project.
it can't be confirmed that someone can get a reward from the bounty they do, so just do it and don't have high expectations...
Even projects that we see have no potential and are actually paying off, surely many have experienced this. it's hard to be sure of a legit bounty right now so if you really have enough time, then just follow all the bounties and don't give up because maybe one of the bounties you follow will pay you a lot.