well, I will explain why I trust the bounty campaign that I follow will be successful. I've been following bounty campaigns for so long, I've been getting bounties in every bounty campaign and I've trusted one manager, often managers who I trust get a new project I'll join soon.

Why did you call the bounty campaign passive income? After all, to get awards you need a lot of things to do

Yes. You are absolutely right. It's not possible to know trustable bounty. I think we should participate in many bounty and we should wait for good news.

Incan assure you that bounty is not a waste of time. If you choose the right campaigns you Can earn in average a 500-1000$/month event if it takes kit of time.. for me it’s like a second job

One of the reasons why I still join in some bounties and believe in them is because I do believe in the manager campaign of the bounty.
Commonly, the bounty manager with their good track record and experience will serve the good bounty )although it is not the only one term to consider).
We can trust them to analyze their bounty program that will be managed.
Besides, to avoid such scams, we must be also careful and smart in choosing the right ICO for the bounty. Learn the project, token supply, allocation, and the softcap reach.
Of course, we cannot guarantee that the bounty is not the scam, but at least, we can try to avoid it.

I am not sure what I am currently following because all the achievements have not been maximal, and as long as I follow the bounty 50%  scam 50% will be paid with a token that has value.

And to know the ICO scam or not fixed does not have a definite benchmark because I am also random in finding bounty and only rely on a trusted manager in every project that he handle.

Your observation is right but there are still legitimate ICO that will conclude and still pay. You can identify good project through the concept in their white paper, Is the concept realisable, can it solve any mankind problems. Who are the team members behind the project, what is their experience like? Have any of them been involved in any of project before. With little time you can get all these info to enable you make an inform decisions.

I does not take a lot of time and something you earn quite a lot.

Not a waste if you pick your bounty choices after doing some reseasrch and not just pick the most paying bounty in terms of tokens! For example some bounties have a total give away of 50k and other have of lets say 3mil, now the give away ICO with 50k reserved for bounty an do a 5x after it is launched and the one with 3mil can go down a lot, so its imp to pick the bounties after doing a lot of research.

The fact that there is a lot of scam has to do with lack of regulations and penalties for questionable and illegitimate ICOs that have promising projects, but mostly fail to deliver on their promises as they are SCAMs. As for the bounty, it is extremely difficult to identify the reliable ones. But it is possible provided you did thorough research on each project you are going to participate in. First of all, the team. Who they are, what they have already achieved in the past, what companies and industries they come from. Secondly, the idea of the project, how relevant it is. There could be a nice white paper and roadmap, but the product could be some crap. And last, the feedback from the subject matter experts should be reviewed and evaluated, because mostly if the project has got a good potential, the experts provide well grounded feedback. The bottom line is you can find one project with great potential instead of 10 scams. But this project could shoot out and make you some nice profit. Therefore, having said all above, it is worth to participate in bounties!