Wormholes make the best shortcuts in the universe. That’s true in a literal sense, since the theoretical things can connect distant corners of the cosmos (or even different universes), allowing a traveler to go someplace without having to visit everywhere in between.
But wormholes also present the perfect way for writers to get around that pesky speed of light, the universe’s speed limit and impediment to fast travel through the cosmos. If characters in science fiction aren’t taking months or years to travel between worlds, a wormhole is likely the reason.
Too bad, then, that as far as we know, the things don’t exist.