Usually you earn tokens worth very little with airdrops (but you don't need to do actual work). Bounties it depends, I have earned very little sometimes (worthless) or I have been pleasingly surprised with more than USD 500 worth of tokens. I only do bounties for projects I like and invest myself, it is a way to earn more tokens you like on top of your investment, like the cream on top of the pie.
i havent join any airdrops since then,but regarding bounties well i have tried a lot and most of them are greay.they dont just promise the profit but when the token has been released to coinmarket the effort is worth it as i am recieving good amount .so for me its bounty that can make good earnings than airdrops that today mostly are scams