Of the many bounty managers you mentioned, all of them have escrowing token rewards, but there are also projects that they hold fail in the market, but what makes the difference is that when the bounty ends, each manager has a responsibility in managing after the bounty ends, the most different is bountydetective, every project he manages always limits participants, both social media campaigns and signature campaigns
Not all the bounties of those bounty managers are escrowed. The payment distribution of some bounties is handled by the project teams. But we can trust those bounty managers because they have a good reputation and are very experienced in managing a bounty. They must do deep analysis or research before they decide to manage a bounty. And they must inform us immediately if there is something wrong with the projects. So, we don't waste much time working the bounties. So, not each bounty managed by the bounty managers can be successful, surely there is the possibility of failed bounties among them.