some airdrop still worthed to participate especially retroactive airdrop that specialized for early user in certain platform. If we just join airdrop program with filtering i am believe we will get nothing or maybe only waste or time. Most airdrop program use FCFS scheme which make us has low probability to win. Just like bounty campaign, we should screen it to find the best one.
Participating in testnet airdrops can also be a good choice in addition to retroactive airdrops, because so far if we look at both airdrops it is still possible to generate income for us than participating in telegram bots airdrops because most airdrops are run through telegram bots nowadays almost all of them are scams, only a few which actually pays and the prizes are also very small, so far I'm personally only interested in participating with those two airdops.