If you want to be safe, look for the bounty of the projects listed on the exchanges. For me to find good bounties I will be looking for good bonus managers, and bounties are appreciated by the community.
It's unsafe, the campaigns are still scam and do not make payments. I have been stuck in two such campaigns this year, they delay delivery for 3-5 months or stop bounty and no return date
Delayed distribution of tokens always happens in this market, so it's too early for you to assert them to be scam projects. Give them some time and see what they will do in the future, I believe the projects listed at the exchange will distribute tokens to bounty hunters, whether sooner or later.