Study the project team. Developers already have successful projects in the past. How the idea of the project is interconnected with the blockchain technology. Study the white book. And if everything suits you, then you can participate.
I think that's the problem. Maybe the white paper and give a lot of knowledge about the project, but as mentioned above, the projects really became too much. And this means that scammers and bad companies. This increases the amount of white paper being studied.