Without any Doubt , I always prefer Bounty because Bounty will reward me for my hard labor whereas Airdrop is like as a free gift without any work to except filled up a simple Airdrop form. Though most Airdrops are fake, but All Airdrops are not Scam. An Airdrop is a free giveaway of premised coins, moreover Airdrop is a fast way to get a large number of users, and it's easy to get a strong community.
You should try referring people to join airdrops, because there are many airdrops that pay you for sharing the referral link.
I know one guy who said he made 2500$ from the Ontology airdrop for example- so this is nice money.
Also, you can do the same for bounties. For example Bountyhive has a referral program , where you get paid every time a referred person joins a bounty from their platform.