Apparently my new phone has a "Selfie" button which when pressed, made this

3. How it mounts on the camera.

4. And this is how it looks in the darkness (with X-T3 set to night mode!).

Sorry for the abysmal image quality.  These images were taken with the iPad Air and significantly cropped, and then their sizes were doubled in the editor. 

Other small Nikon bodies don't have the option of a vertical grip with controls, either: D3x00, D5x00, Df, D7500. Nikon probably think that since the main selling point of mirrorless is small size and reduced weight (I know there are other reasons), adding the control interface to the bottom of the camera body would make it slightly larger and so they didn't want to do it. Or, it was an oversight and they didn't think anyone would want to buy a small camera only to make it large and heavy by adding a grip. But, because of the limited battery capacity the product turned out with (at least in CIPA ratings; I know people get more shots in practice in typical use), they decided to make a battery pack (not a grip; grips have shutter buttons and typically other controls; with the pack there is no way you can hold it from it and use the camera, thus it is not a grip) as an afterthought.  Since the camera was not designed to take a grip, they can't make a grip without making changes to the camera body itself.

I wouldn't call it "crippling" but it is product segmentation. Nikon are trying to find a way for mirrorless and DSLR to coexist and the way they go about it is to design each to be optimal for a subset of photographic applications. Mirrorless is supposed to be small and light, hence no vertical grip.  However, I am sure that by now Nikon will have gotten sufficient customer feedback to design the option for a battery grip into the next higher-end models of the Z lineup.

Now, how the 58/0.95 fits into this logic, don't ask me. ;-) Different people working on different projects within the company. Note that Sigma's heavyweight Art series is very popular and they took over Nikon as the second largest lens maker so clearly there is a market for highly corrected lenses that are not limited by a weight budget. Whether there is a market for extremely expensive highly corrected lenses that are not limited by a weight budget, that's a whole different question. Zeiss make the Otus series and the Milvus are quite large and heavy as well, so Nikon made something similar expect with one stop larger aperture. I can see that it's a bit of a sport. 

I personally like vertical grips (especially integrated ones) but I can appreciate that sometimes light weight and small size are just the right approach. All the other lenses in the Z lineup and roadmap except the 50/1.2 and 58/0.95 seem compatible with the "mirrorless is for reduced weight and high quality" philosophy.

Iron Recycle Company at the Canal

Z6  50/1.4

Impressive image and engine, the Z6 really deliver crisp images