Writing itself is a convenience and time saver to avoid memorizing and repeated vocal recitation. I don't disagree that there is a continued march of convenience, I'm just not convinced that there is any justification to the idea that there is a “this far and no further” point at which thst March stops being a net gain, and even less coonvinced that that point is conveniently just before the convenience advanced of the last few years (or even generations).