I am thinking about some of the conversation that was taking place about American Dirt when it came out (this may have even been a part of the BookBrowse discussion) as I answer this question. Jeanine Cummins chose a middle class mother as her main character. This allowed readers far removed from the situation to more easily put themselves in her place and possibly feel more empathy for migrants and the choices they make.
I think Lefteri's choice of fiction is due to a similar reason. Nuri and Afra were middle class parents trying to survive in the midst of a never-ending civil war. They lost their livelihood, their son, their home, their sight, and their mental well being. I have more in common with them in many ways which allows me to more easily imagine what I would do if I found myself in their situation. I am able to feel their pain and sadness, fear and uncertainty. Lefteri gives me a different picture in my mind of whom is fleeing Syria than has been presented by the media.
If a reader has an emotional reaction, he/she may feel empowered to attend a protest, donate money, or write letters to Congress about how the U.S. is responding to the crisis.