If you have the opportunity to participate in airdrops, then I don’t think their is anything bad in it, but we should know that not all airdrops are going to pay, some might end up being a scam, and some might not really pay good amount of money. That’s why when participating in airdrops, the best thing to do when participating in airdrop is dont have high expectation on any project, because you might end up being disappointed at the end.
But I also saw some airdrops asking people to pay them little amounts of TON or Tron, in order to put them in a better place in a leaderboard.
Some of them do request that you make some transactions which you will be charged little amount of Ton for the transaction, but it’s a choice, if you don’t wish, then you can just decide to participate perform their normal tasks without putting any money.