Answer: Readers might not pay much attention towards flat characters due to them not expressing or experiencing any motives, emotions, or a leading persona in the story line.
Step-by-step explanation:
A flat character is a character with minimal or no nuanced emotions, motivations, or personality. During the plot of the story, they show little to no change, making them not the main focus of the story.
On the other hand, a round character is a character that has a well developed background, motivation, emotions, and persona. They are typically the leading characters in a plot line, and gain a significant amount of recognition from the readers (or audience) due their intriguing character development.