I don't believe in "coins" that require their users to shill and do social media tasks to earn an airdrop. Infact I would actively avoid such projects. If a coin or token is good and innovative, word of mouth will be enough to create some organic buzz, which is way more impactful anyways.
Those are the belief of many bounty hunters because they've been doing those kinds of jobs for so long that out of 100% only 10% are paying and the 10% will be in the next year or more and the total of the paying Airdrops you could get is 20% out of 100% because most of them are fake and non-existent project. they have another agenda when they wanted you to follow their social media pages. But if you are consistent in doing so, without any involvement of cash deposit from your side then the chance of getting some earnings from those jobs is positive but you don't know how much you could get due to the rarity of the legit airdrops.