The final Infinity War trailer presents a terrifying, monumental threat to earth. Armies clash. Dead bodies are strewn about the screen. Music blares. Impressive percussion stirs up emotions. Lightning cracks. And at the center of it all is… Thanos! The terrifying universe-destroyer! Who, unfortunately, looks like a bald purple plastic mannequin with weird grooves in his chin to make up for the fact that he can’t grow a beard.

There’s no kind way to put it: Thanos isn’t impressive; he’s ridiculous. A villain named after death should look frightening, maybe with some sort of visual reference to death. Instead, Thanos comes across as an over-inflated cousin of Grimace from McDonald’s marketing. Except Grimace is actually kind of scary.

What went wrong at Disney’s special effects shop? It’s no particular mystery. The superhero craze has been facilitated by the amazing advances in computer graphics. CGI makes it possible to show Reed Richards’ body stretching like taffy or to portray Dr. Strange blasting mystic bolts of eldritch energy. Superfeats can be portrayed on film in ways they never could be before. In 1978, Superman posters promised “You’ll believe a man can fly.” Now, cinema can make you believe that a raccoon can shoot blaster guns and that Thomas the Tank Engine can grow to terrifying life-size. Anything is possible.

But to be more precise, anything is possible as long as that “anything” has slick, clean lines. This works pretty well for heroes. It makes sense for Iron Man’s high-tech billionaire-funded suit to be all hard edges and shiny surfaces. Even the monstrous Hulk works okay in CGI; the clarity of his features makes them more expressive and sympathetic, which is good since viewers are supposed to sympathize with him. CGI makes him look slightly unreal, and therefore less frightening than he could be. But that’s fine, since he’s not supposed to be frightening. He’s one of the good guys.

But villains are a problem. Superhero antagonists are meant to be terrifying, not generic or distractingly goofy. The slick definition of CGI makes Ultron look like a toy, not a threat. The CGI alien invaders in The Avengers are so blandly drawn that it’s difficult to even remember what they look like five minutes after they’re offscreen. That’s not even getting into the out-and-out disasters, like Doomsday from Batman v Superman, where the effort to render crusty, rocky horror in CGI makes it look like Henry Cavill’s Man of Steel is engaged in a life-and-death struggle with a poorly rendered cartoon. Or Ares in the final Wonder Woman battle, where a personal, face-to-face confrontation between enemies suddenly became a glossy, weightless video game cutscene.

Traditionally, the most visually impressive villain designs have involved more scrappy, traditional methods: makeup, prosthetics, costumes, and a healthy dose of ingenuity. The orcs and monsters in Peter Jackson’s Lord of the Rings trilogy would have been a lot less impressive if WETA had tried to construct them all digitally. The original Star Wars trilogy’s Jabba the Hutt is so marvelously, viscerally disgusting because of the genius of the film’s puppeteers — a genius brought painfully home when George Lucas inserted an ill-conceived, rubbery CGI Jabba into later editions of the films. One of the scariest villains of the last 50 years, Darth Vader, is just a man in a mask.

Sometimes the best villains are often just talented actors being villainous, without any digital aid at all. For Peter Cushing as Grand Moff Tarkin or Heath Ledger as the Joker, special effects are superfluous. Michael Keaton just being Michael Keaton in Spider-Man: Homecoming was considerably scarier than Michael Keaton swooping around in his Vulture costume because the visibly human version of the character was so much more nuanced, personal, and specific. It’s no accident that the most visually successful superhero villain of the last few years is Hela from Thor: Ragnarok — a character where the CGI add-ons were all external and didn’t interfere with the core design, which was basically just “Cate Blanchett in goth makeup.” Hela’s menacing, flamboyant CGI horns are an undeniably inspired flourish, but they’re just a flourish. The Ragnarok effects team used CGI to push a solid design into glorious over-the-top camp, rather than relying on the computers to bring across the entire weight of Hela’s menace.

The problem with CGI villains isn’t that CGI is bad in itself. Used on characters that are meant to look disturbingly unreal, like the shape-changing T-1000 in Terminator 2, it’s an effective way of conveying an uncanny-valley alienness. The problem is that superhero filmmakers too often use CGI as a shortcut for monster design. CGI offers a lot of advantages and flexibility, and it’s an obvious go-to in creating characters like Thanos, who’s never really drawn as fitting into normal human dimensions. But CGI villains date poorly and rapidly. As the state of the art keeps getting pushed forward, last year’s CGI characters look steadily worse by comparison. Darth Vader in Star Wars is still chilling and intimidating 40 years after he first hit the screen. Justice League came out last year, and its villain, Steppenwolf, already looks cheaply rendered.

Computers are great tools, but they’re no substitute for the physicality of a human face and human expression. They’re also no substitute for imagination, inspiration, and a willingness to reassess when your cosmic purple threat looks like the love child of Vin Diesel and a prune. The real struggle in superhero films isn’t for world dominance, but to determine which will dominate the future, CGI or the accessible emotions of a visible human actor. In Infinity War, as far as Thanos is concerned, CGI won — and it looks like the audience lost.