It all depends
For instance there are many factors to consider when joining bounties,as the bounty token price may be overprice, or project overrated, or the bounty manager is not sincere, and end up not giving zip, so it has something to do with a little bit of luck.
Just a little bit of luck and lots of patience, bounty campaign these days are not as profitable as in the past, that's why there are only a few people who are still joining bounty campaigns because sometimes it could only be a waste of time. I'm not discouraging it though, just do the due diligence when participating in a bounty as time is precious.