I think you're trying to make an argument similar to those arguing against "retina" displays, i.e. there is some minimum perceptual angular resolution for sound, so information finer than that is pointless? I think you're either underestimating the perceptual resolution or assuming a very small screen at a large distance.

I think that kind of resolution is good enough to overlap a lot of task focused screen fields of view. I have experienced a pretty clear "central" sound stage within 30-45 degrees or so with regular stereo speakers. That field can imply a lot of subtle positioning within it, not even considering wild panning mixes. I'm talking about the kind of realistic recording where it feels like a band in front of you with different instruments near each other but not colocated, like an acoustic ensemble. Obviously you cannot shrink this down to a phone at arm's length or a small embedded control screen and still have the same amount of spatial resolution crammed into a very narrow field.

When I sit with a 14" laptop at a normal distance for typing, it is also easy to distinguish tapping sounds along the screen. I just did a blind test by closing my eyes and having my wife tap the screen with a plastic pen. The interesting question to me, though, is whether that is just perception via the binaural sense, or really incorporating some intuition about the screen's structure. It's response to a tap does clearly vary by distance from bezels and hinges...

Impressed that you took the time to run a quick test. Spatial compression is a hard problem though, the most expensive sound bars are easily beat by a cheap 2.1 setup. Phones are (mostly) still mono output even though a speaker out the top and bottom (perpendicular to the viewing angle) would be a win for watching videos in landscape, probably because the improvement wouldn’t be noticeably appreciated (enough to be economically feasible, anyway).

Interesting research all the same, of course!