I'm watching John Wick in a movie night tonight, and even though I've seen it before I wanna talk about how cool I find the worldbuilding. Not because it's super detailed, but because it's very evocative.
John Wick feels like the entire criminal underworld has been planned and fleshed out. All the mechanics and details of it feel very planned ahead of time. But if you think about what's really revealed in the movie, it's not that much. There's an organized criminal underworld of hitmen, they have some elaborate system of codes and rules, they have their own legends and myths. But the precise details and mechanics of all that are not necessarily elaborated on.
In invoking the details that they do, they evoke the idea that there's a rich world beneath it, but they don't spend a ton of time elaborating on those details. Doing so would get in the way of the action spectacle. The world feels alive and thought out without overplaying its hand.
Tangentially, this is why I get annoyed with so many movies doing what are effectively isekais for their worlds. Think, for instance, of the Mario movie. One of my biggest issues with it is that Mario came from our world into the Mushroom Kingdom. I just want him to be from the Mushroom Kingdom. Often when I bring up this complaint, people say "but how would we learn about the world?" John Wick is going to be my answer to that question going forward. The movie spends almost no time explaining its world, but you learn about it by watching people brought up in it interact with it.
John Wick's worldbuilding is super fun and intriguing and I wish more movies learned from it.