Are we talking science, or are we talking fiction?
I agree, if we are talking about technology, and only a story with realistic hardware, then there's going to be a problem.
The phrase from Coleridge is, I believe, a willing suspension of disbelief, that is, regardless of the absurdity of what is being described, we still want to believe.
If the hardware is all that we're interested in, then we're talking space horse opera. In the westerns, the vision was of a cowboy--and his horse: a horse opera. Without that trusty horse, the cowboy was lost. It was opera because sometimes, the cowboy was a singing cowboy.
Today, instead of the horse, there is that darn spaceship, or even a starship--I like the sound of starship better. There is much of this.
I suppose there will soon be a boy and his nanobots. But this has already been a plot of one of The Outer Limits episodes. (I was quite moved by it.)
I don't believe it is the technology that makes for a willing suspension of disbelief. The operative part is the willing, and what will make us want not to disbelieve.
I know that those who have come of age after Steven Spielberg can't see believe anything except super special effects--now. Do mass audiences ever really care how correct anything is? And even more for those of us who are not part of the mass audience, is not ours an unquenchable thirst for some humanity, regardless of how erroneous the "tech" may be.
I suspect science fiction will be around--its subject is not technology; it is humanity striving to survive amidst technology.
See Gattaca.