You sit with your eyes closer than half the width of your screen? That is either a HUGE screen and/or you sit with eyes less than 14" away, which is at least novel?

Of course you need two of those screens to fill your field of view, unless you have a square screen that goes below your desk, but I'm sure that's available somewhere.

I’m near-sighted, and checking now it’s really more like 90-100° horizontally, but moving my eyes outside of that range without moving my head is actually not comfortable.

My subjective impression is that the nonperipheral visual field isn’t square. I would find 3:2 displays optimal, or maybe rather 16:11. While a 16:9 or 16:10 display could be extended vertically to fill more of the visual field, that extended portion is not large enough to usefully fit a second monitor there (without head movement).

Eyes (lenses/retina) are spherical with roughly (slightly more than) 100deg field of view each and a little more than 20deg left/right overlap at the nose. That gives a total range of almost 180deg horizontal-yaw and 100deg vertical-pitch. You don't even notice most eye motion... if you did then every time you moved 2.5deg you'ld think about it. Apparent field of view is made up of many saccades that allow your much higher high resolution fovea to cover the interesting parts as it moves/scans/jumps around. By the time you're +/- 10deg from center, you've lost 5x in resolution.

If you're like most people and the horizontal field is close to max, you'll do better stacking monitors than putting them side/side. Inter pupillary distance is a bit over 2in (~65mm), but that's usually small compared to screen distance, which is why I say roughly square (~16:14).

https://en.wikipedia.org/wiki/Fovea_centralis