It isn't just about the technical problem of how to preserve/read digital information.
Back in the day (get off my lawn!) it took a lot more thought and planning to create a document, without instant digital editing etc. Those old letters, books, et. al., took a lot more time and effort to create, and were considerably more difficult to edit and modify, and as a result, tended to have more forethought and planning before putting words down.
As a result, penning a few paragraphs or an essay or two wasn't such a casual endeavor as it is today.
Now that any monkey with a keyboard (and a little cut-and-paste ability) can create volumes of prose, the signal to noise ratio is a lot lower. IMHO, we don't want or need to preserve every piece of text (or image) ever created. The problem is, how do we tell the signal from the noise?
Even if we were able to preserve all digital information across time, nimbly leaping from one format or platform to another, would we want to? And if we did, what a vast amount of garbage! Might as well preserve all our landfills, in case future historians have a desperate need to pick thru them...
Of course, the NSA is probably already doing this, and has just the search algorithm to target YOU, citizen!