@Fakhrulenclix people who immediately after receiving their tokens sell them on any exchange without even worrying about the future of the project, just looking for a few quick bucks, I don't blame anyone for what they do with their coins/tokens, but it's funny that they later regret not having patience in a world (crypto).
You are right, there is no guarantee, but it is the obligation of the person participating in the bounty to do a search (DYOR) to find out if that project is really good or not. If a user does not do a search and then receives a payment that has no value, it is not the fault of the project or the team, it is the person who does not use their time to search. We must educate ourselves.