No, not all science fiction shows or movies accept subluminal (faster-than-light) space travel as normal. Science fiction as a genre encompasses a wide range of imaginative and speculative concepts, including different modes of space travel. While some science fiction works do feature faster-than-light travel as a common element, many others explore alternative methods or limitations to interstellar travel.
In some science fiction stories, authors and creators propose concepts like warp drives, hyperspace, wormholes, or other forms of exotic propulsion systems that allow characters to travel faster than the speed of light. These concepts are often used to overcome the vast distances between stars and enable interstellar travel within reasonable timeframes.
However, there are also science fiction works that adhere to a more realistic or near-future approach, where subluminal travel is the norm. These stories might focus on the challenges and limitations of interplanetary or interstellar travel within the confines of known physics. They explore the difficulties of long-duration space voyages, time dilation effects, generation ships, or even speculative technologies like cryosleep to bridge the vast distances.
It's important to note that science fiction is a highly diverse and imaginative genre, and different creators and storytellers can have their own unique interpretations of space travel and its limitations. The choice of whether to include faster-than-light travel or stick to subluminal speeds depends on the creative vision and narrative needs of each story.