Bounty campaign isnt a waste of time. You just need to look for a good ICO to join. Ive joined several bounties, Ive got scammed only once then I learned that I shoudl check the details of the project first before participating.
It is obvious that participation in bounty campaigns on average brings in revenue. But the level of this income is very different for different people. For people from poor countries, it is very interesting, for people from rich countries is less interesting.