I think bounty is better than airdrop because it has a limit of people who take part in and the coin volume is not much when it's sold on the exchanges from the bounty participants but joining the bounty is more difficult than airdrops and the value is higher .
Yes, it's right . Many coins or tokens from airdrops seems worth nothing and even it's only rubbish coins or scam coins and I only join the bounty to get some valued coins once They're listed on the exchanges.