We know some only airdrops are worth it to spend your time and advertise it because you can get a good reward once it legit .
But the bad side of the airdrops after several months of promoting their project you waste your time once the project is failed or if it's scam. Airdrops is look like a bounty campaign because they are same because they a lot of scam but only some is legit
I'd say if you are somewhere between 12-18 years and has no job - airdrops are good investment of your time since you can gain profit out of your time.
However if you are a grown up - there are plenty better opportunities to gain profit out there and than you can invest in good projects