This is actually a problem with more than just sci-fi shows. There has been an arms race of drama where most stories try to intensify the drama by artificially increasing the stakes so that every story has to have bigger consequences than it really needs to. After decades of stories galactic threats and saving the entire universe, it seems too small scale to save just a few people, or fight for an idea.
This has been something that has bothered me for a while - when the stakes are raised to being an existential threat to humanity/the world/the universe when they don’t really have to be as a cheap gimmick to increase the drama, and then the story/characters don’t actually act like you would expect them to act if the stakes were actually that high. I wrote more about this trend a while back about the film Sunshine, which I think is one of the rare examples where an existential threat is reacted to non-frivolous way, and it’s a story that takes it’s stakes seriously.
Having everything be an existential threat just leads to stakes fatigue where you lose all the drama you’re trying to cultivate because people are numb to the scale/importance of your threat in your story.