For me, these are also biased especially for some devs or teams behind retroactive airdrops, because they are the ones who will know it first, they are the ones for sure will take action first to qualify in airdrop for sure, and there will be still a lot of manipulations.
Could be true for individual team members but otherwise projects usually allocate team supply from distribution.
IMO, retrospective airdrop has been successful only because there is only positive in creating and distributing tokens. It brings hype, and projects get lot of treasury, and community get free money. It's win-win situation for parties involved.
Couple more potential ones:
1) DOP testnet:
https://doptest.dop.org/Incentivized testnet, should take 10-20 minutes to complete tasks.
2) Redbellynetwork:
https://RBNT.zealy.ioZealy quests are useless most of times but this Twitter response [1] from RBNT team made me do it.
[1]
https://twitter.com/RedbellyNetwork/status/1704364030280999071Because most of the zeely campaigns run for coupole weeks or maximum a month. you are right aobut Zeely campaigns are mostly useless but sometime they really pay good rewards. plus zeely tasks are easy and mostly just social media activities.
not sure about others but for me They are Better than joining those airdops where we need to invest in different ways such as staking or bridging to be eligible. I don't mind joining those airdops too but whenever I see free one like zeely or any others I definately want to join.