I think you can get a good Airdrops if that airdrop from real and trusted site. Like airdrop stellar from blockchain and airdrops from market
You were right, I occasionally joined airdrop if I know that the project is legitimate to join but if they aren't, ain't wasting my time in joining.
Like for example, I'd joined Latoken airdrop yesterday because I know they are a good project as I have known.
Ain't considered all airdrops are good and profitable to join, there are some of them may lead you from scam so be careful in participating airdrops not all are a legit one.