It's a gimmick priced as 2.5 monitor stands.
Other combinations of distances and virtual sizes can be calculated in the same manner.
My work setup as a 43” monitor set about 1 arm’s length away. I can just touch it when my fingertip if I stretch slightly. In a virtual space, I’d probably go slightly larger, maybe 45-48”, pushed a little further back.
0.85*0.85 => 0.73
But then, you usually don't buy a 4k screen because you can perceive the individual pixels either, unless you are creating content that requires that.
I suspect it aligns easier with the quality concerns of reality and not with virtual components - if I can use a monitor through the screen with no noticeable loss of quality or additional eye strain, there's no reason to think a virtualized monitor won't be at least as good.
Apple can do amazing things, but they do also fairly regularly make terrible things.
It really lends itself to the phone being a tool, rather than a device for endless entertainment. It also suggests it is an accessory, with the desktop/laptop being the home base, rather than the phone being a primary device.
It really bothers me that the phone is now at the center of the ecosystem. It seems like the hub should be something that isn't as vulnerable (to theft, loss, or drops) as a phone.
Wash. Rinse. Repeat.