Individuals that perceive the composition can empathize with others in familiar situations, they can recognize individuals and even understand how narrative thoughts could come together because it is familiar. Establishing relatable elements expands the scope of the piece, changes it into something personal, something that can convey a concept into the very thought process of others.
While establishing the connection with the piece creates a given level of interest, it does not guarantee that the piece will have enough innate interest to keep the viewer engaged.
The most fundamental element of any narrative that grabs an individual's attention and keeps it is adaptation.
Every narrative, every piece is driven by the fundamental concept of human adaptation, individual adaptability. People are naturally drawn to stories because of the innate fascination with observing how other people adapt to situations. Regardless of whether it's how someone would adapt to the death of a loved one, the stress of saving lives, catching a murderer, caring for a child or even switching careers the interest is piqued.
Since most people are unable to experience all the possibilities of human adaptability they are innately drawn to experience these adaptations through others. It doesn't matter if it's called coping, overcoming something or character growth, it is human adaptation and we are always interested. Mixing relatable elements into the piece only assists in emphasizing our interest in that adaptation.