The problem I'm going to describe did not occur to me until very recently, when I got a super ultra-wide monitor (32:9 aspect ratio) and tried playing videogames on it.
TL;DR: the scenery is stretched near the left and right edges of the screen due to how projection onto a plane works. Question: why isn't the standard to use "spherical" canvas instead of a plane?
I tried several games and I noticed that the objects displayed far left and far right on my screen are stretched and appear way too closer than they actually are. I could not figure out any general setting (field of view, focal distance...) to mitigate this uniformly, until I realized how projection works.
The way 3D objects are displayed on a 2D canvas is as follows: the camera consists of a point (focal point) and an infinite plane (canvas). To calculate where another point in front of the camera will be displayed, this point is connected to the focal point and the point drawn on the canvas corresponds to the intersection of this line with the canvas.
No wonder the far left and far right parts of the screen are so stretched! The rays from these vertices intersect the canvas at a very small angle.
This problem would be eliminated if we chose the canvas to be a sphere, ideally with the same curvature as the monitor (in case the monitor is flat, the sphere degenerates into a plane and we have the same situation as before). That way, if we choose a correct position for the focal point (depends on our screen setup, curvature, aspect ratio etc.), no stretching should occur, since the focal point is literally "surrounded" by the canvas, instead of the canvas running away from it in all directions.
So my question is, why isn't the standard to implement this "spherical" projection instead of "planar"? Is it because it happens on such a low level of coding that developers don't care, or the code with spherical projection would be a serious bottleneck compared to what is done now? Or the market with super ultra-wide resolution is so niche that they don't care, but we should expect to see it sometime in the future? Or the standards are so baked in that nobody cares about implementing something new, even if it would make more sense?
Sorry in case this question doesn't quite fit in here, I actually don't know anything about making videogames, but this strikes me as it's more about geometry than actual game-making.