You have to choose the bounty that has a good and reliable manager. If you are feeling depressed that your efforts were wasted that's the other side of bounties.
If they aren't able to reach their soft/hard cap they will never pay your efforts so if you want to get paid with the bounty you are joining. Just choose the bounty that has an experienced bounty manager and assures the participants to get paid.
I also believe that you need to stay close to the proven bounty managers and follow their companies. And in General, all the platforms that exist today, there are a lot of participants, and there is absolutely no sense to work there.