There are too many factors to be worried about, I think it's not worth the risk.

1. Signature campaigns comes and goes
2. They don't have equal payouts, very few are high and many are low.
3. Most won't keep to their promises, they will fail to pay up.
4. Most bounties pays a month or more after the campaign ends.
5. Too many scam projects.
6. Many good projects don't use bounties for advertising their projects anymore.
7. Imagine you wake up one day and this website is no more.

Too many reasons not to rely on counties, a job in the real world is more reliable.