Yes definitely you can earn! some bounties pay immediately and you can earn money from them. But some take lots of time. You have to chose them wisely.
Delay distribution , locking period and long time campaign is the reason why many people need to wait longer to recieve payment . You already advertise the project for long time but in terms of salary distribution they are making it difficult for hunters to clam ,that only want is to have a fair distribution of payment from what job they've done.
This is why I agree with those who suggest that the bounty program/airdrop program should be escrowed to avoid this problem.
On one side, bounty hunters should be blamed if they promote bounty scams because they don't do a deep analysis.
But on another side, bounty hunters are one factor who will make the project successful being accepted by most people and should really be appreciated by the project developer.
So far, they only obey the project developer, they do what the project developer wants, but they (the developers) do not appreciate what bounty hunters have done with their project, and this is not commendable for them.