I have not seen such sites. Moreover, I can say that sites with rewards for work are often unscrupulous. You can wait for the withdrawal of your money for half a year or more.
As I said coinbase never gave me anything, nor to another user, but other users did recieve funds and never had such problem, I think you kinda need to use their service to actualy get them.
Blockchain.com airdrop was instant and I done it for a looot of people irl
, same goes for keybase which has ended a while ago, but BC will have more airdrops. Needs kyc anyhow.
Not sure what kind of sites you mean geornis or what you mean by unscrupulous, perhaps you mean bounties, signatures are usualy fine and the users make the spam.
A signature campaing doesn't make a service legit anyhow.