I don't think you should really be concerned by airdrops now. This is because lots of the ones out now are just shits. Some after getting a whole lot worth nothing, some worthing a ridiculous amount compared to the amount at hand. Someone even said to me that the era of good and promising airdrops have long gone by when people made quite a fortune from airdrops. However, despite this claim of mine, the fact remains that there may still be some airdrops that are good out there, which means anyone can still keep trying as we may have nothing to lose just to register and wait for the turnout
I agree. However I still keep eye on airdrops because there are gems once in a while. Some promising ones recently: twist, enumvio, Bitcoin white, hellbiz and all airdropalert exclusives

I suggest airdrop hunters to stop wasting time on 5-10 tokens, you can make more than that if you put same effort somewhere else. And ignore ref programs as well if you don't have any big group where you can fish for referrals.