I recently watched this video, and while I found the concept interesting I'm still really not clear on what makes voxels so much more efficient than polygons. The artistic implications are pretty neat (voxels are undoubtedly a more flexible modeling medium than polygons. I'm not sure if they're flexible in a way games could actually make much use of, but that's another question), but how is describing a model as a set of cubes more efficient than describing it as a set of triangles?
The general consensus seems to be that you can put a lot more voxels onto the screen than polygons (though I assume this is greatly offset by the inherent inaccuracy of voxels), but I haven't found an explanation for why. If anyone could link me to a good video/article on the technical reason for this, I would appreciate it.
Even if they do truly offer a much greater level of geometric detail than polygons, from my own (admittedly limited) experience with graphics programming I've found post-processing to be a much greater bottleneck than rasterization, and I don't see how voxels would do much to change that.
If voxels (or a hybrid solution) are really the way of the future, why are polygonal engines still so dominant? Are there any major drawbacks that aren't being addressed? I'm genuinely curious.