I was actually thinking about this yesterday. My gut tells me that like the leaker implies, ultra wideband is all about enabling AR. When the glasses finally do hit, devices (and things) can have whole new levels of experience emerge from them, and the glasses will know precisely what angle the viewer is seeing the devices from.
imagine you, wearing the Apple Glasses or whatever, get a notification from your AppleWatch. You glance at it, and emerging from the face of the watch is a 3D interface that you can interact with directly. If anyone has seen the older Final Fantasy: The Spirits Within movie, many of the interfaces are like this, including the one the lead interacts with on her wrist computer.
We shall see. Apple is testing and developing and teasing all of this stuff over a several year period, pretty much out in the open (ARKit, U1, LiDAR, etc.) and I think that whether it’s in 2021 or 2022, we are getting closer to those Apple AR specs.