I have used Crew3 and I am still on the platform, I'll say that it is more useful to the project than users. Most users might get nothing in return for their activities on the platform however the project get rewarded with free working community. I think Crew3 needs to do more to protect the interest of their users, I find Galxe more useful to users though.
Crew3, galxe, bluemove or even guild are the new trend to increase users interaction and gain active users. It seems the era of having bitcointalk social bounty is surpass by this kind by easily participating on the platform. Before I am joining a lots of social campaign, and now this is the trend and more appreciated since nft are included on the process for completing task. Its like an automated bounty manager have secured it for cross checking via blockchain and smart contract.