Here's why:
* Narrative focus: The story primarily revolves around Katniss's actions, thoughts, and experiences. We see the world through her eyes, and her choices drive the plot forward.
* Character development: Katniss undergoes significant emotional and physical growth throughout the series. We witness her transformation from a young girl to a symbol of rebellion. Peeta's development is also compelling, but it's secondary to Katniss's arc.
* Thematic significance: Katniss embodies the themes of survival, resilience, and the power of the individual. Her actions directly challenge the oppressive Capitol, making her a central figure in the revolution.
* Author's intent: Suzanne Collins, the author, has repeatedly confirmed that Katniss is the main character.
While Peeta is an equally important character, he plays a supporting role in Katniss's journey. He provides companionship, love, and a different perspective, but his actions are often driven by his relationship with Katniss.
Therefore, while both characters are essential to the story's success, Katniss Everdeen holds the title of main protagonist.