I am not sure it is correct to say that science says Ramayana and the Mahabharata are myths (meaning not real and only made-up stories). It is just that from the scientific point of view, there isn’t sufficient evidence to treat the narrative of the epics as historical accounts.
Of course, historicity is not established with direct evidence alone. There can be demonstrable correlations of the linguistic variety, archaeological findings, popular oral traditions which can together form the basis of what might have been an actual historical Ramayana and Mahabharata.
But as things stand, even establishing such a basis seems difficult. As per Puranic chronology, the events of the Mahabharata — the more recent of the two epics — are dated to roughly 5000 BC. This alone puts the events of the epic farther back in time than anything else known to present-day historians, to whom the birth of the Buddha itself is “ancient”. The oldest imaginable times in terms of human civilisation don’t go further back than ancient Mesopotamia and Egypt.
What little we know about the cities of the Indus Valley Civilisation tells us that these were contemporary to Mesopotamia and Egypt — existing somewhere between 3000 BC and 1500 BC.
This conflicts with the view held among some in India who believe that the events and people of the epics happened as far back as 15,000 BC (some even say 30,000 BC). These ridiculous estimates do two things — they make Indians look monumentally stupid, and they place the epics so far beyond the pale of recorded history that the only way any conclusion about them can be reached is through faith. Last I checked, faith was not a tool in the historian’s kit.
It is highly unlikely that anything resembling archaeological evidence could have survived from seven thousand years ago, especially in tropical climates as unforgiving as India’s. Things don’t get frozen here, they wither away.
I would like nothing better than to find evidence that India’s antiquity extends farther back in time than we think right now. It will blow my mind to bits if and when it happens. But I think we do a disservice to this country’s intellectual traditions when we treat every fallen bottle cap and dry leaf as reason to scream that the Ramayana and the Mahabharata are historical accounts of events that happened in ages past.
If we are honest with ourselves, we will realise that there are people in many countries who have similar views about their culture’s antiquity. We need to be humble enough to realise that the reason we put our claims above theirs has nothing to do with objective scholarship — it is instead a matter of national pride.
There is no shame in admitting that we might never know some things. We should keep trying to uncover the past of course, but if we don’t find what we would like to be true, we should not take that to mean that somehow India and its civilisation is less because of it.