They do. Marley had control of seven of the nine titan shifters for a very long time, and through that, they were able to dominate over the rest of the world for a very long time.

But they were starting to lose their edge as the rest of the world progressed technologically, and they needed the natural resources in Paradise to retain their edge. The only thing standing in their way was the Founding Titan, which was being held by the Reiss family, so a mission was launched to retrieve it, and through it, the resources on our island.