It's almost the same actually, the bounty program and the airdrop,
Both were different. If you're seeing the purpose of bounty and that to boost the project in the various things related with social media while airdrop is just a way to create awareness for people who joined in the airdrop but it does nothing for the project other than giving away free token to be sold by airdrop participants.
even many bounty projects are phishing and scams, airdrops also have promising potential in the future, depending on how they develop in the future.
Airdrop didn't even look promising again. Too much scam airdrop and i have seen complaints about that everywhere. This's why relying in the bounty as a job is a big mistake.
I hope that people will not do this. they will still need a real job.