Of the five ways the article says to earn tokens without investing and mining, I like and love bounty and airdrops. For me, bounty and airdrops are the best and easiest way to earn tokens for free. So I recommend bounty campaign and airdrop.
Bounty and airdrop campaigns are not the same as the investment to the legit projects. The bounty hunters don't have to worry if the team talk about the late distribution because I don't think the bounty rewards are the equal to the passive income. If you are interested with airdrops, you should observe the process of how bounty managers fight with scam teams after unresponsive tickets.