I'll allow for the possibility that our civilization could wind up there in a hundred years, and that the advance of technology on this planet could actually go backwards, but in the scenario I laid out, technology will continue to advance, and even the rate of advance will quicken over time.
We can throw all sorts of Armageddon-like what-ifs into the mix, but the point is, if a culture can survive its own destructive nature, it can advance to levels where it achieves an awesome degree of mastery over the physical universe.
I'll even allow for the fact that not every culture will be oriented to technological innovation. We see this difference between cultures on our own planet.
But, if we can widen the examples set by the various cultures on this planet to extend across galaxies, then we see that at least some of the cultures that may exist out there will take the path that our own has. Ours is one of constant improvement, discovery, and innovation in the physical realm, and there's no indication that this proclivity is likely to change.
An extraterrestrial culture with the same bent toward technical innovation, and with a head start on us, would possess technologies that boggle our minds, and which would seem to us to be straight out of science fiction.
I am in total agreement with that. Actually, their technology would seem more like straight-up unadulterated magic rather than scence fiction. I can just imagine if someone from 900AD (let alone 300 BC) materialized in New York, or Dubai, or Tokyo! He couldn’t even begin to describe what he saw ....reminds me of the part of Ezekiel of the spinning wheel. Hmmmm