I want to point out that the sketchfab player wastes precision for Far Camera Clipping because even a camera with 1° FOV does not show clipping when moved far away
The near/far clip planes are not static, they change dynamically depending of the camera position so you can always see the model. We always make sure the near/far encompasses the whole model
As @shaderbytes said it's a ratio issue (also note that we don't have guarantee of 32-bit precision, it's rather 16 bits zbuffer precision).
In the future, we'll probably add a slider to adjust the near clip plane a bit to give more visibility (at the detriment of the global z precision, but on model like yours it should be fine).