I’ve been thinking about this, in conjunction with quantum computing and AGI for some time.
If AI follows anything like Moore’s Law, I don’t think it will be too long (decades) before we’ll be breaching the limit of 64bit, and we would need to go one way or another.
That said, based on the above, 99%+ of our existing jobs would have likely been fully automated, so the world would likely be a very different place, and 128bit computing likely would stand out as too big of an achievement.