If you are willing to collect a substantial value of coins with Airdrops / Bounties, that's very difficult and you need to research a lot (and of course to be lucky, quite often good research is not enough)
The chance is very high that the failure of such campaigns will discourage people doing it (at least that's my impression).
Unfortunately, the quality of Bounties / Airdrops has decreased a lot. The downfall of ICO business is part of the problem, when I'm scrolling through the Bounty section I don't see any project where I would consider an investment. Most of them are blatant scams, some projects have (maybe) a good intention but a clueless and inexperienced dev team and the last group of them are planning a business model we have seen 100 times before. Such projects won't get anywhere... only away with investor's money
I did a few social media bounties in 2018 but none of them was reasonably profitable.
However, I can't agree that all Airdrops are scam, IF you dig deep, the hard research might be rewarded, like the legit and profitable Airdrop from
Keybase. And yes, such Airdrops don't appear every day. If I could vote for something I would vote to get more Airdrops like that in crypto space. Airdrops are very effective to distribute coins in a decentralized way and if it's not a shitcoin, most holders won't dump. The problem of Airdrop dumping is not the Airdrop, it's poor quality of the coin. Almost nobody will hodl a crap coin (they will try to sell it ASAP to get out) but many will hodl a good coin.
I'm still positive that some of the better projects launching in 2020 will start something similar. Or start a good bounty here because it would be easy for them to stand out from the crowd of shit- and scam projects. But then, the project has to offer something new - not just empty promises.
So - not all Airdrops / Bounties are bad, there are still good ones - but very hard to find.