Question about Men's dress shirt construction. Ins Sewing Machines Parts and Sales in Los Angeles

Here is a picture of a shirt laid out flat, and as you can see, there is as much up front as there is out back. Hence, that’s why the seams/joining areas are at the edges.

However, this design assumes that a person is perfectly symmetrical sideways! Some Most people aren’t symmetrical sideways! In this image, the man has much more in the front than in the back.

Is there a reason to adjust what percentage of a shirt’s material is out in the front to improve the fit?