And the simple answer is, Yes. It can.
Lack of realism can be jolting, and pull you out of a story, but being too real can do the same. In my opinion there is a fine line that must be walked. Each story needs a different level of realism, depending on your audience, and the purpose of your story, but there are a few principles that I think should apply to basically every story.
If you are writing a high fantasy where great battles take place… Your soldiers (and ESPECIALLY your main character) cannot come out of these clean. I mean really. There needs to be some dirt and grime and icky stuff on them. But you don’t have to SHOW the blood splatters. Cause quite frankly, that can become rather gross very quickly.
Another thing I saw in a novel I was reading a while back, was the main character was traveling a very long way. Many trials afflicted them on their journey… But you know what stuck out to me?
They never got tired. They never needed to rest.
Mortals get tired, y’all. And if you have a demigod being trapped in mortal form (Thor, for instance), the mortal form WILL need sustenance and rest. Kind of part of the gig.
Think of Aragorn in the Two Towers. Wounded. Exhausted. Barely able to ride. But he makes it to Helm’s Deep. That has such a bigger and deeper impact than if he had fallen off that cliff, and just stood up and walked there, without a scratch, or blood, or being totally wasted and worn out.
I would never advise you to put content into your story that is too mature for your chosen audience. But even a child will notice lack of details in a story if they are well read. And for certain the story will have more meaning to them if you include just enough details as to not steer their mind into every little thing you want them to see, but to point them in the right direction and set their imagination loose.
Don’t be gruesome or overly mature. And don’t spell it out.
But don’t skimp either! Realism and details are important!
Real life isn’t real… so our stories need to be! And the reality of that is… that we have to tell the truth. And if you lie about a character being tired, it just lessens the impact of the greater ideal you are trying to get across.