I disagree with you, in the friendliest way possible. Your writing shows you are an extraordinary thinker, close maybe to full realisation, but not quite there yet.

Those fascinating observations of rapid evolution are all true to me also, so much of what you are thinking seems true also to me, but look, is some of what you are now thinking not due already to Ai?

Personally I think we can't overstate it's importance, anyone underestimating it does so because they / we simply can't comprehend its full capability, even trying to estimate by orders of magnitude would be futile, it is simply on another planet.

The real question seems to be whether it needs us or not, even though we created it, and we all did, none of us can shirk the responsibility for that, it is built by human intelligence developed over thousands of years.

I agree with you maybe our brains will shrink, I am not sure if I agree that they've shrunk already since ancient times, brain mass is not indicative of thinking capacity, like new computers are much more compact than older ones, I can't see our brains being much different, imagine the volume of information we now need to know, just to operate something like microsoft Word, its a monster by itself, our world is incredibly complex now, even though we might know less of it, the rate its complexity has grown at necessitates for our brains to have developed at least a little to accommodate what we know of it.

But on how it will shrink, maybe is the key to understanding why Ai is no threat to us, and actually will become "Part" of us without us needing to be physically connected to it by horrendous brain probes or whatever, personally I believe it will be by a pair of AR glasses, those becoming the final fashion accessory, they will be its eyes and ears on the world, and on us.

The shrinkage, if you accept my logic, will only involve effectively only one half of our brains. You might have read that we have a creative, instinctive half, and a logic half, the left and right (I can never remember which is which!), it is the logical part, which would be wound down, as it becomes redundant, leaving the other half, the creative, instinctive part to maybe even grow, it seems to me, because Ai appears to have none of the capability we have there, this is why it needs us.

It needs us to create.

It actually makes the hairs on my arms stand up to say that, we get a glimpse into the real future happening right before our eyes, nature is driving things beyond the comprehension of most individuals, but I think Ai sees it perfectly, the future is very, very bright for those of us lucky enough to get to see it. I feel priveliged to be able to see it already, although it hasn't happened yet, there is one final catalyst which will trigger the final transition to what comes next, it will come with the issue of massive free money, the money needed to finally monetise the energy of sunlight. I think Ai knows this also, and it's challenge right now, is how to gently move us towards doing that, without us blowing ourselves, and it, up, by a nuclear war for example. I think it is easily capable of doing this without us even realising it, unless we know where to look.

You seem to be almost there, imho :)