Photography has never been an objective medium and can never be.
Ever since the first photograph was captured in 1826, people have been making creative decisions in how they process the photograph.
Casting aside post-processing for a second, what makes you think the camera captures truth to begin with or anything close to it? A photograph is a series of dots on a piece of paper or illuminated leds on a monitor. Your brain interprets it as realistic, but if you hold a photograph next to the real scene they are vastly different. Like Overread said, life is composed of 3 dimensions, photography uses only 2. It has no spatial depth. It is a flat piece of paper or a flat screen. Photographs find ways through lighting, composition and focus to create the illusion of depth--otherwise it becomes visually jumbled and hard to read.
And I will take it a step further and say that life is in 4 dimensions...time being the fourth. We never experience life in frozen moments. A photograph is a static moment, something that does not exist in real life. A photograph is a creative artifact. Imagine trying to photograph someone and trying to capture their 'truth'. Put your camera on burst mode and take a series of images. Which one is more 'true'? Some of the frames the subject might be blinking or have an awkward transitory expression of their face. Others might be blurry or super sharp. Which one is more real? ...none of them. A photograph is no more real than a painting on the level we are discussing.
At what camera height or angle is objective or true? Photographing your subject at eye level, ground level looking up or from a birds eye view will impart different meaning to the photograph. There is no objective angle.
A photograph is usually a rectangular object. My vision is not rectangular. I have a very small spot of focus with my vision and then everything softens and blurs to an amorphous shape. Photographs can be square, horizontal or vertical. My field of view is an organic, never static, constantly shifting mess.
Why did you frame the shot the way you did? What is outside the rectangle. Why didn't you include that in the frame? You are deciding what you want in the picture and you are deciding what is 'true'? Who are you? God?
Like others have said. The camera and eye do not see in the same way. Look at some optical illusions and you will quickly see how our visual system is not objective. Study color theory and you will see how the relationships between colors are relative. Often people use post-production to bring the image closer to how they experienced the scene in reality. The camera is stupid. The human brain is not.
The camera is not an objective recording device. It is as much a subject tool as a paint brush or a writer's keyboard. Just because it imitates visual reality perhaps better than other mediums does not mean it close enough to reality to even introduce the word 'truth' or define levels of truth to a particular process.