I began to think this would be a waste of time with everything I learned because almost all the projects I had followed ended in scammers. Is this a waste of time for me? 
No, you need to search more carefully for the new bounties, research the bounty project team, idea, technology, etc. before participation. There are many similar scam bounty, need to learn to distinguish them from real projects. Also, need to look at the bounty manager and his previously bounties.