As of today, there are still potential income in airdrops and bounties but not the same way back 2017-2018 where in a lot of great bounties scattered here in forum. Bounties that can give you a great amount of income like 4 digits and even 5 digits in usd.
It all depends if the project is good and with a strong team behind. Nowadays most airdrops are from meme tokens to increase their holders count and even if we receive millions of tokens its just worth less than $1.
As of now, Bounties are the best way to get crypto without investing any money, Only time investment.