for choose bounty or airdrop to earn token i think , we must take a part of bounty,
why? because in bounty most of them project has success and we are participant of bounty get the token from our work.
in now so many airdrop is scam, and if you just trusted in airdrop in my opinion you will get nothing token from there.

i choose bounty because not all bounty has scam, and
percentage bounty to scam is low i think. thankyou

i hope this will help you to answer this question