It reminds me the scam scheme of donating to receive a bonus for the donation you have just done. It's definitely not a giveaway or airdrop, as such offers don't involve the participants having to give money from their own pockets to participate. These offers can demand you to complete a task, but you give only your effort in counterpart for the final payment. Even if you hear some people saying it's legit, I believe it's not a good idea to join, because there is a high chance it's a ponzi scheme.

Unfortunatelly crypto industry is full of scammers and I risk saying there are more scammers than ever right now. Very few offers are legit these days and worth to be executed for small amounts of profit.