I know someone that told me he made $6000 from a bounty. I saw some that later become profitable. There were many that become useless and no much profit compared to the time spend to promote them in social media. Some are completely scam. I can remember one which was called student coin. It was a scam. People wasted their time.
Bounties are just lie how altcoins is. It can be profitable. It may not be profitable. It may turn to scam.
Some bounties are signature campaigns but payments in altcoins. I do not know why those are on bounty board because they are signature campaigns. Payment are in USDT and can be profitable.