So what should a designer or a developer be doing now, to make things better in 10 years, or 100 years?
It seems like a cheap answer, but it needs more people, with more perspectives, trying out various answers to this question.
I suspect the greatest long-term leverage comes from providing people relief from the cognitive load of fighting for food, shelter, health, transportation, and education.
Those are heavy goals that lots of people have spent lots of time shifting only very slowly. The little-Alan-Kay-in-my-mind replies, "We need better thinking-tools in order to do it faster", which I can half-believe, but beyond that, I get stuck. I don't see how to work backwards from that to a first step that can actually be taken.
I see equality in computing/storage/access as another great need, but teaching the world to write javascript isn't the solution, and "AI"s which do your shopping aren't either. I'm not sure where to place or how to phrase my imagined future, but the path there isn't a slow ascend (or decline, think "phoenix" - we're slowly approaching a locked in world). Maybe what we need is inspiration, a grand vision of the new world.
We also need to look up from our phones and teach our young to understand, see and act upon the world in greater time scales, unlearn our short-sighted perspectives and teach the next generation to care for their future generations, something we're failing to do.
Edit append: We also need culture (music, arts, etc.) to help us think.