I'll sidestep a default comment about Joseph Campbell and just say that a journey requires choices. And choices reveal character and advance plot.

Because the cinema is usually a car ride away...

This is how I look at it: A character arc is a metaphor for a journey, so whenever you have a character arc, the character is moving from one point in his life to another. By having a physical move, the metaphor is reinforced.

This sounds so much like a drunk question.... Why do so many movies involve characters.... But seriously, movies take journeys because that's life. You go from point A to B and once you get there, you're changed. We love doing it, audiences love seeing it, and movies like BURIED only worked because we went into knowing it wasn't at all anywhere close to reality. Was it entertaining? Yes. But laughable, full of logistic bullet holes and the ending, though necessary, felt like a big stinking cheat. Maybe some would disagree, but in the scene where he thought he'd died, it felt like a good moment and to end on and I was packing up to leave. The False Hope ending just felt so tooled.

bailish hits on the big point: Story is at its core a psychological journey, where a character begins in one psyche state and ends in another. [There are many variations on this including stories where the Protagonist refuses to change or the Protagonist doesn't change, but changes others, but in most stories, they go through some sort of metamorphosis]. The fact a major character such as the Protagonist does go through a transformation, switching from one world view to another, does lend itself to stories whereby they journey from one geographical site to another. There are also these other dynamics: * We like to see new places and different cultures. Journeys do that. * When a character moves from their Ordinary World to an Extraordinary World, it puts them on the defensive and creates more in the way of obstacles and challenges. * Staying in one place is generally less cinematic than going to a new environment. * Journey as a metaphor for life. Many other points out there, I'm sure. The main thing is, as with the previous questions, to be conscious of a variety of psychological possibilities these narrative dynamics have in terms of the reader.

I think it goes another way too - studios don't take a chance on movies that they aren't familiar with, eg. movies with no "arc" or "journey" or whatever fancy words the execs have now all picked up via Save the Cat. Louis CK's new show is proving that their can be stories without the traditional elements that every exec looks for and every screenwriting guru writes about, and just have a story that is engaging because it has a vision and an unique voice (something Woody Allen used to do so well), but stories based on the personality of the stroyteller or the voice of the writer are harder to make posters for, so they don't get greenlit. it's a cynical trend, determined by disinterested people.

I believe journey is the ultimate and inevitable dynamic of life. I'm not a physician and whether right or wrong we can pick up Einstein's suggestion that time doesn't exist. It wouldn't be the time that passed, but us. We crawl through processes, stages of evolution, and we use the concept of time as a compass. What matters is we are not static. We can't avoid being on a journey, from the most pragmatic to the most existential sense. We find our meanings in change and comparison. And so there's infinite journeys. A biological one (birth/childhood; adulthood; old/death), a mythical religious one (Campbell wrote about it), a cosmic one (morning; afternoon; night), and so on and so forth. Cooking is a journey, and so is a political campaign or a deep meditated introspection. We can't be bleak, we're always starting somewhere in order to go somewhere else. In the middle, we participate in life.

I think journeys are common in stories because they echo our own travels through life. As we navigate life, we make decisions and choose between alternatives. Sometimes we know the consequences of a choice, sometimes we don't, and sometimes we know where a choice will lead but don't care. Notice how even the language used to illustrate this point is loaded with the imagery of a journey? It is difficult to find neutral words. To illustrate, what is the core difference between the atheist and the believer? Between the naturalist that thinks life's origin is explained by evolution or the Christian that trusts in the existence of a Creator? One has chosen to believe in the existence of God and the other has chosen not to. What a difference that single choice makes. Life is a journey, choice is powerful, and the future beckons to us all.