for my own experience in airdrops.
3 out of 25 airdrop that I have been joined are legit and those 22 airdrops are all scammed that I didn't get anything token from it.
Most legit airdrop is from docademic

I have statistics of 10 out of 50. 3-4 coins are traded on exchanges.
Do not waste time on airdrop, too small payments