Augmented Knowledge System, Yes. Borg, No
We have always had a bandwidth problem. For example, read a book a week for life equals only ~3,000 books out of 143 million unique titles. So the real issues are finite time and thus quality vs. quantity.
As for infinite human recall, we do not need it. The value of books, machines, and the Internet/cloud is that they are the on-demand sources of infinite recall. This issues is access finite time and thus quality vs. quantity. Doing that biologically makes no sense.
So what is really needed are databases of reliable knowledge, separating the best from the rest. That is better on-demand augmented knowledge systems. (Full disclosure, this is what my company seeks to provide.)
And, of course, there will be many of these databases and systems because in a world of ubiquitous, ambient conversational interfaces no one will tolerate unreliable knowledge being given to them on the fly. (If you are interested, on my Medium publication, A Passion to Evolve, there are numerous articles on this topic.)
While a cognitive interface seems a logical linear trend, it has a nonlinear reality. To wit, the most important comment made in your piece is, “once our thoughts control computers what stops the opposite being true?” That is, indeed, where the rubber meets the road.
The “distribution of shared knowledge and experience universally,” means either the cacophonous noise of everyone everywhere thinking/talking simultaneously or somehow eliminating the redundancy — borg-like — again, a quality vs. quantity issue.
[Btw, comment that, “We have outstripped evolution through intelligence and ingenuity by escaping the sentence of genetic death from almost every disease,” is over the top.]
Clearly, you have a fertile imagination. But even if you goal is science fiction, the narrative has to cya on plausibility. Thus, if you think we should be a borg, say so and go for it.