The best literature stands alone, in time and space. The world that created the Epic of Gilgamesh no longer exists and is completely alien to us. And yet the epic is reskinned every century for a new audience. Things change and yet everything is the same.
Maybe you're not old enough to realise. I was a neophile too, once.
In fact, rereading your post I'm not even sure where you get the idea that I'm a "neophile." I have no particular interest in the contemporary. My argument is just that the past cannot hope to comment comprehensively on the present or future, which I think the analogy with science makes pretty clear. Things genuinely do change. Our genes change, our technology changes, our philosophies, sciences and religions change. I agree that the past has much to say about the present and a really informed person could not possibly ignore it, but it simply doesn't follow that we don't need any more literature or new ways of telling stories or interrogating our lives.
The GP's frustration, I believe, lies in the fact that you've been presenting the trappings of modern society as if they're the bedrock of modern existence; as if the findings of a science article today act on the soul the same way as realizing a dead Russian wrote a cartoonish parody of the actual personality one has cultivated for twenty years (a reaction I see commonly!). All writing may share similarities, but not all writing is literature, and recognizing that distinction would resolve the disagreement you first posted.
Many analysts would say the limiting factor of Plato on today's audience was not the total population, but the shift in interpretations (and related, writing) which make it so difficult to translate. And still, classics departments are offering fresh takes on the works, even through the 20th century, radically shifting the meta-level conclusions that we teach as takeaways. I hope you can acknowledge that this is more due to the underlying human nature which the works speak to, rather than some inherent unending depth to the writing - and that literature as a field carries this interpretive depth as its activity, rather than just cobbling object-level tools to interrogate their premises.