The day before we met, László Nemes went to see a superhero movie. He didn’t last long. “I found it unwatchable and false, boring and self-referential, a world of ideal people who don’t behave as humans but more like machines.”

He smiles. It’s tea-time in the Islington, north London branch of Caffè Nero and Nemes gently explains that such films infantilise viewers in two ways. The plots let them defer responsibility for the fate of the world to demigods; the way they are shot – lots of signposting, everything carefully controlled – offers a false sense of omniscience.

“I’ve been extremely saddened by the way cinema has narrowed its language and created an alphabet that’s never been poorer,” he says, sipping his water. “Superhero movies take away mystery because there’s nothing in the shadows. All is revealed. And that’s not how our relationship to the world is, because, unfortunately, you can know only a fraction. So it gives a false impression of our might.”

Genre fans must be terrible worriers, he continues; prisoners of “an extreme state of anguish” soothed only by narrative certainty. “Superhero films let people put away their fears. But this ‘saving’ is not very realistic. And if you create only objective films that avoid big questions of life, then we just create machines to eat popcorn.”

Nemes is not going to make a superhero movie. He could if he wanted, though. Right now, Nemes could make whatever he liked. Three years ago, his first film won an Oscar, a Bafta, a Golden Globe, the director’s prize at Cannes and almost everything else in-between. An immersive account of life at Auschwitz for a Jewish prisoner forced to work in the gas chambers, Son of Saul earned awed acclaim for its gravity, ambition and formal virtuosity.

The experience, he grins, “really created a sort of positive trauma. A reference point that creates all kinds of expectations. So I’ve been trying to cope with that.” Hard partying and snowdrifts of coke? Nope. Nemes’s strategy seems to have been to create “trying to remain responsible and to respect the audience”.

And that means a follow-up just as demanding as his debut – albeit for different reasons. Sunset puts us in the Austro-Hungarian empire on the edge of anarchy in 1913. Our heroine is Irisz Leiter (Juli Jakab), who returns to Budapest and the hat store once owned by her late parents. The world she meets is confusing: does she really have a long-lost brother? Why are the new proprietors of the shop so sinister? Is Irisz swept up in the insurrection or is she somehow its engine?

Sunset is a knotty and haunting fairytale. It shares Saul’s distinct visuals: camera either closely focused on its lead’s face or following hard on their heels at head-height. You get less information than they do. It’s intentionally baffling, potentially frustrating.

“Sunset is really about our perception of the world,” shrugs Nemes. “It’s a labyrinth. The audience has to accept confusion as part of the process – and people don’t like that! I have come to understand that it creates major anxiety. But that is the challenge and the promise: to experience the world through the eyes of someone who is not a god. Then you’re not just a popcorn-eating machine, you’re someone for whom this experience can become personal and subjective and meaningful.”

Nemes was born in Hungary in 1977, moved with his mother to Paris aged 12 and read international relations at university before studying film-making in New York. He worked as Hungarian filmmaker Béla Tarr’s assistant before Saul and Sunset, and now wants to make a movie in English. For the past six months he has lived in London with his wife, a clinical psychologist at UCL. He loves the layers of history here (“Budapest is a city of ruins”), the different nationalities (“It creates a different vibration”), the easy access to 221b Baker Street (he’s a slightly unlikely Sherlock Holmes nut).

I first encountered him on the film festival circuit back in 2015 and while friendly, he was also guarded and wary. Today, he’s lighter: relaxed, even playful. His English is halting and experimental; he speaks with much less severity than comes across on the page. Back then he was indignant about a rise of antisemitism in England. That he has since moved here is cheering – and curious. “Well, I’m still really concerned,” he says. “Anti-Jewish feelings are definitely very alive and now coming from the left, and that’s rather puzzling. I don’t think people realise how pernicious that is.”

Still, he says, at least it’s better than Paris. “That really hurts me. When I moved to France from Hungary I was so relieved at no longer having to be scared of intolerance. Then, such sentiments would have been ostracised or at least repressed. Now, in many schools, teachers are scared of talking about the Holocaust, as if there was some sort of competition for suffering.” He blames “state TV propaganda that fed the population in the 80s and 90s. It united people. And so now there’s a payoff.”

He continues: “Antisemitism has always been a barometer to measure the moral temperature of a civilisation, for almost mystical reasons. The Jew can go unseen. They are hard to distinguish and so can be the threat coming from inside. Today, it’s therefore very alarming. Almost like we’re now past a critical point.”

Géza Röhrig in Son of Saul

Sunset is more than a historical study. It is a warning that sophisticated societies can combust. Actually, it’s a prophecy; Nemes thinks it inevitable that we will follow suit. Not because of the political tinderbox, but because we can’t stop fiddling with the matches. “I really have the feeling that a self-assured civilisation such as ours is preparing our own destruction,” he says. “Even Europe at the beginning of the 20th century, this incredible whirlwind of creativity and positivity, was already longing for its own demise.”

I must look a bit downcast. What can he say, he grins. He’s from Eastern Europe, fatalism is in his blood, Kafka taught him that while humans struggle to build meaningful things, they are also digging their own graves.

So: catastrophic self-sabotage is old news. Nothing to get especially upset about. What has actually got Nemes fretful is, it turns out, computers. They’re making it much, much worse. “We take from our brains so much power and give it to machines,” he says. “It’s unprecedented. Likewise the incredible amount of imagery we’re producing and the fact so much is virtual. We are building a sort of narcissistic image of ourselves through social media that means we perceive people as potential angels. There’s an increasing self-righteousness, and a great moral expectation on human beings I don’t think is realistic. Then there’s a backlash when we realise we can’t meet this ethical standard.

“I would love to be wrong, but I really believe that democracy and the internet are not compatible. New technology channels so much of our darkness and we are blind to it. And sometimes the accumulation and spreading of knowledge means people reach a new level of ignorance.”

Nemes feels like a throwback. He engages in the kind of intense mental pingpong I remember only from university. With his Little Prince notebook and his 2am tousle, he could still pass for a student, even at 42, with a shelf full of silverware. He also treads lightly and seems the real deal. I can’t remember the last time I talked to someone of my age with no visible smartphone.

Juli Jakab as Irisz Leiter in Sunset. Photograph: Venice Film Festival

Recently, he says, he has found himself in situations in which communication was impossible. Where he was speaking to people who couldn’t think freely because they had been enslaved by ideologies fed to them by the web. Who believed themselves individuals while reciting mass rhetoric. “So much aggression,” he says, shaking his head. “For the first time since I left Hungary I found this oppression of having to adapt my discourse to a sort of well-received set of ideas. It’s extraordinary that internet on a voluntary basis creates a new form of totalitarianism. One that is much more dangerous because people think they are free.”

He sighs. Identity politics trouble him for reasons that reach back to Saul. “I’ve never been called a white man until recently,” he says. “But now I’m a white guy from eastern Europe who is a Jew. And so I should only speak about such people.

“This is fractioning humanity – and it’s actually reverse racism. It works as racism, but cloaks itself in the beautiful, beautiful dress of tolerance. And that’s extremely dangerous.”

• Sunset is released on 31 May; Nemes is giving Q&As after selected 35mm previews.

• This article was amended on 10 May to adjust the spelling of Kafka and correct a mention of Budapest.