Brutalism is actually the name of a recognized style of architecture.
Kogonada, the director, made his reputation as a video essayist. He has done a lot of work for the Criterion Collection. He started as an academic student of film and then got bitten by the bug to make movies, not just write about them. Columbus was his first feature film.
He was/is very interested in modernism and formalism in film and wanted to explore synergies with modernism in architecture. If that sounds a bit too heavy on the highbrow, theoretical film school level ... well, there's an element in Columbus of a new director getting his dissertation out of his system. I found it interesting enough to watch several of his interviews on YouTube and can appreciate what he was trying to do. But as a filmmaker shooting for a broader audience (as opposed to an essayist for Criterion Collection classic films), he probably needs to rope that down a bit.
His second feature film, After Yang, is a sci-fi film centered on artificial intelligence. It was supposed to release this year but it's in COVID post-production limbo. I imagine it's done, but it's the kind of film that was probably intended as a serious entry on the festival circuit, and that's all up in the air. It's not a tentpole but it would be a shame for it to go direct to streaming with no publicity campaign. Kogonada is obviously a very smart guy who wants to make "intellectual" films. The trick for guys like that is to move beyond the art house scene and find some traction with mainstream audiences. Especially because the theater model may be dying for good due to COVID and the wholesale move to streaming.
Columbus got rave reviews in the festivals and has a 97% critics' score on RT. It got no marketing campaign and only about ten people saw it in theaters. It's streaming on several platforms now and has a considerable and growing following from the word of mouth buzz. I wouldn't call it a "cult" film because it doesn't have any of the edgy weirdness that I associate with that word. Adrenaline junkies hate it. People who have the patience to get through the first 15 minutes rave about it. Columbus was a huge, out-of-nowhere surprise, and Haley Lu Richardson should have won an Oscar. There are high expectations for After Yang centering on the question of whether Kogonada could do it again.
I had no idea “Brutalism” was the name of an architectural style. Those are the ugliest buildings ever made by man.