New projects conduct airdrops during the process of token sales, which is a fairly common guideline. But there they benefit more because they want to engage in a lot of promotion activities and many people who come from airdrop are then encouraged to invest in their project. They power their market by promising to give away just a few tokens to everyone. Besides some bad projects who distribute million tokens only to airdrop participants but most of those tokens are worthless.
It is very surprising how some of you have been in crypto for some time now and yet still very blind to what is happening around you. You seem to be speaking like a newbie in crypto even though your account suggests otherwise. It will be much better if people like you don't make comments about airdrops when clearly you have zero knowledge about them.
I will suggest you go do a little research about airdrops and how it has been giving 7 figures to participants, more than what you will earn in 7 years of signature campaign.