I have joined a lot of airdrops, I don't know whether it's a waste of time or not, but many of them don't pay and it's also not uncommon for those who ask for eth or btc after the airdrop is finished.
thats why you need to do some research before joined an airdrop campaign from any project mate if you don't want to regret
because some project don't pay their participants and sometimes they will pay you but the token has no value
regards