Yes, it impossible find the scam bounties campaign right now, even some one would like to say check their whitepaper or the team, but now, all this scammer will create the promising whitepaper and the official page, you can identify it true or not now, you will find you waste time if join so many in same time.
I agree on that it is really hard yo detect scam bounty, i am working as a bounty hunter for almost 3 years but sometimes i was also being victimized by scam bounty. Even if we are extra careful we can not really say that the bounty is scam specially when the project is really promising and has a very amazing platform.