The more people that prepare for these airdrops, the smaller the rewards.
If we're to compare how Dogs performed with their rewards to that of Hamster Kombat I think I do agree with your thoughts that the number of participants in an airdrop project also influences the value of the rewards to be given. Dogs had a few participants and not less than about two months or so, they airdropped their rewards to the small community and it was large. But HK the level of hype got a lot of involved which probably wasn't what the developers envisioned. In some cases, it leads to postponements and extension of snapshots and listing date just to accommodate the larger community.
One of the cons on which a particular project been farmed out by tons of people and a long time duration then it is really that somewhat prone into that being farmed too much or being cheated which we have seen some airdropers who do end up on making thousands of dollars because they have been that making some multiple accounts. Somehow there are really those people who do make some serious profits specially to those influencers or youtubers who do have tons of followers. Is it still worth the effort? Totally depends if you do have the time and having that patience because not all people would be having time and having that effort that they could really be having into. There are some who are really that eager on dealing up with airdrops on which there are those people who do even make it as a source of income on which this is really that very wrong. It would really be always better that you engage out with airdrops on having that approach that you are really that prepared whether it do end up some shit or not.
I do remember those old years on which you could be able to earn or eligible for airdrop on just simply signing up on a google form on which unlike now on which you would really be doing up some hard tasks.
There are even some that do require some transaction counts on which this really spend up some gas fees on which this is really that something that being needing some expense
on which it is really that already that a part of risks on which you do need to deal on with.