OBJ files are a very common format for 3d content and yet Revit, a 3d application, still cannot import them. 3D scans/reality capture for as built models often come in this format and are inaccessible on this platform. Point cloud files also cause issue because they typically aren't view able in visualization add-ins. I don't see why Revit lacks support for this commonly used file format that is well established. (OBJ's have been around longer than I have)