That is one of the price you pay for decentralization. Any project can be scam and many spend a lot of money on marketing to gain peoples trust.
This is actually true, the scenario that we've seen before is like this. Most of the projects held bounty campaigns that has millions of budget to distribute to its participants, those people that helped them to market their project. And as soon as it reaches to the investors, they will eventually like it because many are advertising it but there's one big mistake that they didn't see it coming. It has been planned from the start when they've gained the trust of the people and making them believe that the project is on progress, they will leave eventually.