A photo is a fake reality. It’s a capture of the world from the perspective of a camera that no person has ever seen.
Sure we can approximate with viewfinders and colour match as much as possible but it’s not reality. Take a photo of a light bulb, versus look at a light bulb, as one obvious example.
This is just one other way to get less consistency in the time of different parts of the photos, but overall better capture what we want to see in a photo.