No story is ever just a story — especially mythological epics. The Ramayana and the Mahabharata evolved over long periods of time. You might even say they are as organic as you are (you are organic, right?).
A story becomes a myth over generations, after being told and retold many times over. With each retelling, details get added — local flavours, sub-plots, embellishments etc. The ones telling the story sprinkle the narratives with their own biases while telling the story. Sometimes, other local myths get attached to the main plot and grow alongside it. Historical events get fictionalised and become core parts of the growing epics, with special effects and magic added.
Through no particular individual’s efforts, the Ramayana and the Mahabharata became the cultural foundations of India. So great is their influence that even today, major Indian movies use their plots. In everyday conversations, people compare fights within a family as a Mahabharata and a pair of loving brothers as a Ram-Lakhan duo. I once had a Muslim colleague in tech support who , in moments of exasperation, used to say, “Sab Ram bharose chal raha hai!” This kind of pervasive cultural relevance makes the epics more than just objects of affection — it turns them into items of faith. As a result, when anyone expresses a view suggesting that the epics are anything less than absolutely true accounts of past events, it is taken as a personal offence.
No evidence, except for descriptions within the narrative of the epics, has ever been found to prove that supernatural events and beings are real. Those who believe them to be real do so because they want to, not because they have valid reason to do so. Seefor more on this tendency.