In the time of Plato, only the most educated could read and write. So if you could do both, I think your odds of being remembered had almost as much to do with writing good quality as it did with being lucky enough for your writing to survive centuries.
That's such a good point I've never really thought about. 🤔 Actually kind of a trip to try and imagine a world where simply knowing how to read written text was akin to sorcery.
First, let's consider that up until fairly recently in human society, writing has been the domain of the wealthy and not entirely accessible to everyone. The rich could write whatever they want or patronize those who could write what they wanted for them. The rarity - relative to the greatest developments of proliferation being chiefly the printing press and recently the internet - of written works, demanded that anything someone bothered to put into physical written form must have considerable innate value to someone. If they didn't, nobody would have bothered with the effort or expense.
I no longer have access to the reference for a citation and am having trouble digging it up, but I saw (probably on a blog about AI) some figures recently describing the amount of written "material" produced by humanity on a daily basis (or some other comically short time) in 2023 being comparable to the amount produced in the ~five thousand preceding years since the written word is thought to have been invented.
With as much "writing" being produced, most of it being spam or low-effort shitposting, the signal to noise ratio is unbelievably high. Regardless of the profundity of the thought being born and described, the chance of having anything written today - randomly on the internet - recognized for its quality is infinitesimally small.
I believe that there IS a fantastic amount of truly remarkable writing being done every day all over the internet. Nearly all of it will be retained on some form of media basically forever, even until the media is woefully obsolete / destroyed / the heat death of the universe. Most of it will never be set upon by human eyes again after this weekend.
Today, like hundreds of years ago, what rises to the surface does so due to commercial pressures. If you are awesome and impress a publisher with deep pockets, your words could be preserved in a form that will be read in 2434. Of course, it will have to continue to be impressive long after most of the books selected by Oprah's Book Club.