It's not a waste of time if one is recording profits from doing Airdrops. Alongside airdrop you can carry out some non tasking bounty activities to augment what you get from the airdrop.
I have been doing airdrops since 2017, and I would agree with you. Airdrops represent a good opportunity for the new users, to get some cryptocurrency in their wallets. The amount may not be big, but it will act as a good starting step. And in rare occasions, those who held on to airdropped tokens have benefited by the price rise in the long term. EBTC token is one example.