In storytelling (https://lib.hol.ink/index.php?topic=25.0), tension refers to the stress levels experienced by the listener resulting from their engagement with the story. Writers like to rephrase this in more colorful, "poetic" ways, but that is the fundamental concept at hand. And it is ultimately the responsibilty of the storyteller to manage the story's tension to the best of their abilities, aiming to create a pleasant see-saw within a range of acceptable tension levels for their intended audience.
If there are too many obstacles in the story for the listener's temperament, their stress levels will get too high. And as emotional stress does physical damage to the body, their brain develops a trauma response to the story to protect them.
This results in them being subconsciously pressured to set the story aside, and any time they try to go back to it, they're pulled in other directions. Suddenly, the dishes in the sink are more interesting than that book, or they can't help but check their phone between each paragraph, or they zone off as the storyteller is droning on.
Eventually, they accept that they've given up on the story entirely, serving as a resolution that stimulates their hormones and lowers the tension of the work. Until the story is resolved, that tension is constantly elevating their baseline stress level (which spikes at every reminder), reducing their window of tolerance for the tension in other areas of their life. So it is a natural instinct to give up and make room for more important things.
In very stubborn people who keep engaging in story after story despite the tension build-up, this can become a vicious cycle that eventually leads to things like burnout and depression.
You can imagine the responsibility storytellers feel to ensure they're structuring their plot in a way that doesn't do more harm than good. This is especially important when we're acting as our own storytellers, setting career goals, planning projects, pursuing skills... as well as when we're managing other people as a person in authority.
On the other hand, if a story has too few obstacles, it becomes less and less story-like, and eventually, there is no story at all. The results or information are handed to the listener on a silver platter. The goal is achieved simply by thinking it or reading to the next sentence. This is where things start to feel like textbooks.
We often chase this kind of convenience, because it sounds more efficient on paper, but it actually reduces efficiency in the long run. Because it doesn't provide any hormonal satisfaction (https://lib.hol.ink/index.php?topic=40), engagement is dramatically reduced, and listeners are discouraged from pursuing similar goals in the future.
Imagine a scenario where you're reading a dictionary to learn new words. It's extremely easy, and every couple sentences teaches you a new one. But it's exactly becase it's so easy that it's not very fun, and you are very, very unlikely to continue reading through to the last page.
Instead, you read a few pages, your subconscious realizes how easy it is, then it makes you set the book aside and never return to it. Your brain doesn't want to bother wasting energy on something this easy when there are more stimulating activities perceived to be of higher value. It presumes that an easy activity will always be easy, so there is no need to engage with it until it becomes a survival necessity.
So we can't let the tension be completely relaxed, but we also can't let the tension get too high for its genre.