Every Bounty is different.
If you ask for Twitter, Facebook or any other social media bounty, they are hardly profitable as there are armies of multi-accounts and the real reward for a single person is negligible.
When it comes to making a video or writing articles and you are good at it, it could be worthwhile for you.
Of course, it all depends on whether you do a good research of the project and whether it will be credible and develop, which will make the price of your token reward increase.
It is best to look for stable coins and quickly convertible altcoins bounty, then the reward is smaller, but the certainty of earnings is greater.
All in all, a bounty can be profitable, but a lot depends on your skill at selecting a good campaign.