An actual book stores more data than that and for longer. At that point, why not just etch the data onto a metal plate or something? 8K is only a few pages of text at 12pt. It could easily fit onto two sides of a small-ish metal plate, etched in 8pt or so, and it would last, potentially, for millennia.

This can be rewritten many, many, many times.

What’s the practical benefit of that? If the point is long-term storage, rewriting isn’t a priority (or possibly even a need). And this isn’t designed for capacity.