Airdrop is considerable a time wasting over a hundred of airdrops you participated? Maybe 1 or 5 airdrops are guaranteed for you to pay. Airdrop payments are ranging $1 - $5 also so and this is not a good way to earn crypto currency or Bitcoin.
You don't do that much task compare to doing bounty campaign, i think the amount they are paying is okay because you don't do that much task, it's not really a waste of time if all of them pay but scams are everywhere in this world.