Unfortunately, the people most invested in pushing alternative stories of history are not doing it out of some philosophical sense of solipsistic purity (which would at least be admirably consistent, if still useless), it's the people who have vested political interest in rewriting the past to suit their means, in the sense of "nothing happened in Tianenmen Square on June 4, 1989".
Tearing down our current, admittedly flawed, admittedly biased, admittedly fragmentary understanding of history does not cause truth to miraculously reveal itself, but rather creates a vacuum into which will rush the narrative pushed by the people in positions of power. Who controls the past, controls the future. Instead, we can do the best we can, which is to say: produce documents, debate over their veracity, and keep an open mind as to their inaccuracy.
Or the calculated lies of propagandists. The fact that ancient histories were written with an agenda in mind may be true, but that does not mean they are improved by adding further layers of ‘constructed truth,’ IE, lies.
