Trek was the first science fiction show to take itself truly seriously
Science fiction was not always considered a genre for serious stories or real dramatic performances. That’s not to say that the makers of Flash Gordon and Lost in Space didn’t put a lot of time and energy into their stories, they did, but sci-fi was seen as a campy genre for kids.
The silly genre of science fiction was taken and used to tell real meaningful stories by Trek. The show wasn’t unfriendly to child viewers, but it asked its audience to reach for something higher than just the usual space opera tripe.
Star Trek made you think and made you feel, things many of the science fiction shows of its day didn’t do.
Next: Star Trek evolved