Precise design is appealing to the eye. When a design is off-centered we can subconsciously tell that something is wrong with the design. For some people this can be rather annoying to come across. Using lego blocks as an example for design, if a rocket is built and a window is placed in an off-center location it can ruin the whole design.
Read more about precise design here: https://uxdesign.cc/its-only-slightly-off-center-what-s-the-big-deal-544d868e4b9e