In the long term, humanity is doomed. There is no doubt in my mind. The reason to think that is relatively simple: we are made out of stories and these stories do not work well with technological progress. Y.N. Harari convincingly explains in “Sapiens” that the only reason for us to be a leading species on Earth is that we can organize ourselves using shared stories – religions, nations, money, human rights, …you name it and we will write a story about it. Stories are so important to us that we spend a significant part (if not all) of our lives having life satisfaction as part of a story. For the story’s sake, we rage wars, we do anything to anybody (I leave it to your imagination). Yes, we build civilizations and conquer nature but can we survive the delusion that there is more in life than a good story?
I may sound a bit abstract. Let me give you an example: imagine an authoritarian leader with access to a doomsday weapon. There are a few of them around. Imagine now that the leader for some reason has his back to the wall and there is no way out, except… Except he blackmails the world with his super-weapon, in his mind what is the point in the world’s existence if he (and his people) are to be vanquished? There is no common sense or survival instinct able to beat a fanatic conviction in some story out of which you don’t exist.
At present, there are a few leaders with access to such type of doom device (MI’s “rabbit’s foot”) but the technology advances, and people with such access will multiply with time and hence the risk. At some point in time, a series of bad luck events will result in triggering the device and…
The best-case scenario afterward would be that we will be pushed back a few to 100 thousand years (Stone Age). The worst case will be the extinction of almost all multicellular organisms.
Can I suggest an exit strategy? Yes, but you are not gonna like it! AGI genetically reconstructs (recreates) 42 of the most popular species including humans.