There’s a few things to unpack here —
Regards how human vision works in general :
[ 1 ] First and most relevant to the discussion around FOV is that the eye does not stay fixed. Instead your eyeballs tend to move a lot - and scan a scene with unconscious movements called " saccades ". In order to fixate on objects at different positions and depth in the real world.
[ 2 ] The " act of seeing " also depends on fusing multiple inputs from the visual cortex. While central foveated vision covers only about 2 - 5 ° , and is where we are able to read text or identify symbols and colours. Its an additive process that builds up the mental model of vision.
[ 3 ] As mentioned above " peripheral " vision is largely responsible for the perception of motion and changes in speed. Its something that has evolved in animals - humans over time and changes in IPD also affect sensitivity to scale - distance , speed approximation.
So its not as simple as saying that the inputs outside the 90 ° central foveated area don’t matter. They absolutely do because vision takes in multiple specialised inputs , and is a lot more " plastic " or adaptable in the brain. It still awes me that the images from our eyes - pass through the middle brain ( or " Wernickes area " , the language center ) before reaching the visual cortex.
The world you see before you is a lot more subjective than you think. I’m finding the 140 ° Pimax field of view a lot more comfortable than " Vive " or " Index " where the peripheral information is constrained - or totally missing altogether ? It doesn’t make the image in the center any better but it does contribute to presence.