I don't think anything is free in crypto you will still do some tasks in airdrops to get airdrops and same thing goes to bounty... but I prefer risking my time which is a resource on is own for a project by promoting them with bounty than buying into it
But if some of them do not need it, they make ico and collect money and then they run away.
I think the best thing for now is the projects that collect the necessary amount of private investors and distribute free tokens.