Imagine a world where humanoid robots outnumber people—this a reality Tesla CEO Elon Musk said we’ll see by the year 2040.

Musk's prediction came during the annual Future Investment Initiative conference in Riyadh, Saudi Arabia, on Tuesday.

“I think by 2040 probably there are more humanoid robots than there are people,” Musk told the audience. “Every country will have an AI or multiple AIs, and there will be a lot of robots, way more robots than people.”

According to the U.S. Census Bureau’s World Population Clock, the number of humans currently stands at around 8.2 billion.

Musk has previously heralded the surge of humanoid robots and advanced AI and how it would impact humanity, going so far as to say humans will face a ‘crisis of meaning.’

“If you've got humanoid robots—when there's no real limit on the number of humanoid robots—and they can operate very intelligently, then there's no actual limit to the economy in it,” Musk said at the 2024 All-In Summit hosted by the All-In Podcast, in September.

Experts, however, disagree with Musk’s assertion that the AI robot revolution is nearing.

“Elon has a track record of overoptimistic predictions about AI, and this one is no different,” author and scientist Gary Marcus told Decrypt, contrasting owning a robot to owning a car.

“There are only about 1.5 billion cars on the road; many people can’t afford one or don’t see the need,” Marcus said. “The same will be true for humanoid robots, and we aren’t going to see six humanoid robots for every car anytime soon.”

Marcus is a cognitive scientist, AI researcher, and author of six books on artificial intelligence known for critiquing overhyped AI claims. In September, Marcus criticized OpenAI for not delivering on GPT-5 or Sora, despite being valued at $150 billion.

“Absolutely insane,” he said. “Investors shouldn’t be pouring more money at higher valuations. They should be asking what is going on.”

During the unveiling of the new autonomous cybercabs earlier this month, Musk showcased Tesla’s Optimus robots, which he said would be affordable, with long-term cost projections of around $20,000 to $30,000 each.

Despite Musk's promises of affordable robots for everyone, Marcus said economic and safety concerns, along with significant software and hardware challenges, would make widespread adoption of humanoid robots in the near future unlikely.

“Roomba, the best-selling consumer robot of all time, sells for a few hundred dollars and has sold around 50 million units,” Marcus said. “It’s just fantasy to imagine selling 200 times as many humanoid robots in the nearish term when nobody knows how to build a single safe, reliable, generally useful humanoid right now, at any price.”

Edited by Sebastian Sinclair