In "Things Fall Apart," Okonkwo is considered a tragic hero because his downfall is the result of his own character flaws and his inability to adapt to changing circumstances. Okonkwo is a complex character, who is both admirable and flawed. He is a successful farmer and warrior, and he has risen to a position of great influence and respect in his community. However, he is also stubborn, proud, and quick-tempered, and these qualities ultimately lead to his tragic downfall.
One of Okonkwo's fatal flaws is his inflexibility and inability to adapt to change. He believes that the traditional Igbo way of life is the only way, and he is resistant to the changes brought by colonialism. This leads to his isolation from his community and his inability to unite them against the colonial threat. As the novel progresses, Okonkwo becomes increasingly desperate to maintain his power and status, and his actions become increasingly rash and impulsive. He accidentally kills a clansman during a funeral ceremony, and he later kills a messenger from the colonial government in a fit of rage. These actions not only seal his fate but also further isolate him from his community.
Despite his flaws and mistakes, Okonkwo's tragic end evokes a sense of pity and empathy from readers. Achebe presents Okonkwo as a complex and flawed character, but he also highlights his humanity and his struggles. Okonkwo's downfall is a reminder that even the strongest and most successful among us are not immune to tragedy and that our own flaws and failures can lead to our undoing.