No, science fiction isn't a phase. Science fiction, or scientific fiction, or speculative fiction will always exist. Technology will always grow and progress. We will always continue to move forward. 24th Century Starfleet was not the most scientifically advanced form of civilization.
I think the problem is in our storytelling viewpoint. How does a writer or author present a future further out from the future they're already writing about?
I look at the differences between Star Wars and Star Trek, for example Star Wars depicts FTL technology that allows an individual to travel from the Core World of Coruscant to distant Mustafar in mere minutes, whereas travel from one star to the nearest neighbor in Star Trek takes days. Star Wars presents a mystical "Force" and a cohesive galaxy spanning government. These are speculative aspects that the Star Trek universe doesn't have or hasn't developed yet.