Elements of the film feel very familiar, and on top of that, narratively inconsistent. The story makes a mincemeat over its central debate (the difference between a ghost and a demon), and even gets a key historical date wrong, all while banking on a “based-on-a-true-story” approach to add to the effectiveness of the horror. Then, the film ends with a paean to superstition, suggesting an ardent belief "in the fairy tale" (of an afterlife) rather than in the auspices of science and reason.
It’s all neatly tied up in bows for the audience, but that kind of clear-cut explanation of a supernatural entity’s motivation is the enemy of successful horror, which seeks to foster uncertainty, not bring clarity.
But most horror movies are built around their monster, not their protagonists, and the could be a problem, going forward, for the franchise. We know the Warrens are going to "make it," don't we?