I guess that's just the benefit of early adopters. It's not exactly odd that airdrops (or exchanges that do say airdrops) have to perform/add a lot more in terms of the amount airdropped and possibly whatever more they can add since they're catering to a LOT more of users compared to the past. Yes, this includes bots, but it's up to them really to determine how to filter said out still, the amount would be pretty sizeable.

Considering all that, It's also understandable why good airdrops are rather hard to find nowadays since, well, the projects themselves usually aren't any good. They usually die off after a couple of weeks of trying to stay afloat, and even if there were good ones, they're ruined by the countless number of botters there are, possibly other influences as well but Idrk about those that inevitably lead the project to a ruin. This causes legitimate users who want to support the project to simply fall off. I mean what can a lone man do when a sea of whatever you'd call botters approach him. Nothing.