I like the optimistic outlook and mostly strive to remain so myself.

But……it’s getting increasingly difficult to do that. Evidence your periodic “The Coming Dark Ages” postings.

Would you put “certainly” at 100% ?

We’ve had various prior dark ages of varying durations that we managed to push through and advance the state of humanity (by many objective measures), although it did take centuries.

The rate of technological progress throughout those centuries to the present has been exponential, despite the dark ages setbacks. We’re rapidly approaching what many people consider a singularity, possibly within the next 30 years. By definition of the singularity, it makes prediction beyond that impossible. If you believe the threat of this Singularity (and the recent AI/transhumanisn advances makes me increasingly fearful the Singularity IS a real threat), then a centuries long spaceflight settlement with real biological humans campaign becomes doubtful, at least in the way we’ve all romantically and optimistically envisioned and dreamed about it.