The real trick is textures.
When the photo is laid over and wrapped on the model, it looks great. But once you remove that, the raw mesh underneath is not as impressive.
I would really like to see the examples they had here without the texture laid on top.
The cool part is that this also allows for capturing transparency, and any effects caused by lighting (including complex specular reflections) are embedded into the representation.
There are examples of people outputting SDF (and by extension geometry) with nerf, and projecting original texture onto that would give some nice effects; (live volumetric works best this way) though there would be some disparity where edges/occlusion isnt perfect, so youd want to sample nerf's rgb anyway... although a lot of that is fuzzy at the edges too. A lot of incorrect transparency at edges looks great in the 2D renders (so much anti aliasing and noise!) but less good for texturing
And while it's true that there are methods for extracting a surface from a NeRF, achieving a high quality result can be challenging because you have to figure out what to do with regions that have low occupancy (i.e. regions that are translucent). Should you consider those regions as contained within the surface, or outside of it? Especially when dealing with things like hair, it's not obvious how to construct a surface based on a NeRF.