Rather, there is another reason. There are specially trained people who hunt for bounty campaigns. They can run 100 or more campaigns at a time. That is why there are a lot of participants in all bounty programs.
I heard about these, and then they sell tokens immediately on the exchanges, thereby lowering the price several times lower
That's right, they are not interested in the project and its development. The main goal is to earn tokens and immediately sell them at any price at the opening of trading. Of course, the price of such a token drops very quickly.