I took part in some bounty campaign and the result was nothing. It doesn't work and the payments are so little that makes it impossible to even transfer the tokens and sell them.
I have been paid some of them and it was tokens worth $1-2 for social media campaigns. This is a big joke for bounties and I wonder why are people still doing this.
You asked why, cause this is the available activities that most of the newbies know to do, there are some that are into crypto for long time but they did not thrive to be like an expert trader or even qualified for some bounty campaigns like, content creating, translating or video vbogger, so they just settle to be as a regular bounty hunter