What I understand so far is that already losted bounties prpjects are totally fake and they just want some hype to sell their shit. On the other hand, when hunter gets paid, the price becomes too low to sell even. So, no matter a project is listed or not, it is always better to do enough research before joining.
Correct, doing deeper research is far better than leaning with those campaign who attract bounty hunters to join and participate there's still no assurance that you'll be getting paid, or of you'll receive payments the value was doomed. Take time to dig deeper with the intention of the team and if the project will be usable in the long run so you'll not going to waste your time.