Inside many Amazon warehouses are workers known as “water spiders,” who pick up and move the numerous plastic storage bins used to shuttle goods around the facility, and who restock worker stations with merchandise, boxes, and other material. At a warehouse in Sumner, Wash., recently, a special crew of workers stepped in to help the people moving the plastic bins—humanoid robots.

The droids, made by Agility Robotics, are about the size of a person and can walk around the warehouse floor as well as squeeze into tight spaces thanks to their backward knees. Amazon, which has invested in the startup through its Industrial Innovation Fund, is testing a handful of Digits (as the Agility robots are called), observing how well the droids communicate with its other warehouse systems, as well as how the company’s human workers feel about their robotic colleagues.

For most of modern history, robots that looked like us and walked like us have largely been relegated to movie and TV screens, while the robots in factories and other real-world settings have taken the less-sexy form of mechanical arms or oversize Roombas. That’s starting to change as a new crop of startups make humanoid robots a reality and promise corporate managers increased productivity and a solution to labor shortages. At a time when generative AI is already raising worries about job loss, however, the rise of the humanoids is likely to bring further urgency to public concerns about automation and employment.

The new machines look like something straight out of science fiction. Figure, a Sunnyvale, Calif., startup backed by OpenAI, recently unveiled its 02 model, a sleek matte-gray-and-black robot with six cameras for eyes and onboard AI to help it see and interact with humans. Carmaker BMW has tested a Figure robot at a South Carolina facility. Tesla CEO Musk, meanwhile, predicts his company’s Optimus robots will be in production for internal use by the end of 2025, and the following year for other companies.

Even if Musk’s timeline proves fanciful (as his often do), the billionaire’s impact on the robotics sector is undeniable, says Carnegie Mellon University Robotics Institute professor Chris Atkeson. “When Elon Musk says he is going to create a new industry, people pay attention,” Atkeson tells Fortune.

Equally important have been advances in robotic hardware and artificial intelligence. Nvidia, for example, recently announced a large AI model called Project GR00T, aimed at training humanoids, while OpenAI has launched an initiative to develop models for robotics.

In September, investment management firm ARK published a bullish report about humanoid robots that put the potential market at trillions of dollars. Although the report did not provide any specific timeline, it posited that if the cost of a humanoid robot were to be $16,000, the droid would need to deliver only 5% more efficiency than a human worker to be economically efficient.

How close we are to that day depends on who you talk to. Humanoids can cost around $150,000 each to produce according to a January report from Goldman Sachs (the companies declined to provide pricing to Fortune). Proponents of the humanoid form factor say that costs will only come down, and they talk of the technology’s game-changing potential in ways that can sound utopian. “We’re basically going to live in a world where any physical labor is a choice,” says Brett Adcock, the founder and CEO of Figure.

“If a robot drops something or glitches in an elevator with someone—those things can’t happen.”
Brad Porter, cofounder, Cobot

Adcock’s company has raised more than $700 million since its 2022 founding and counts Microsoft, Nvidia, Intel Capital, and Jeff Bezos, via his investment firm, among its backers. Agility, led by former Microsoft executive Peggy Johnson, has raised $180 million and is seeking more. Johnson expects to produce hundreds of humanoids in 2025 at a facility in Salem, Ore., ramping up to thousands and eventually a maximum of 10,000 annually. Currently, Digit robots are doing real work moving containers inside a Spanx facility, as part of a multiyear deal between Agility and the warehouse operator GXO Logistics.

For all their promise, humanoids still have their limits. Many of the current robots can operate for only about four to five hours before needing a battery recharge. And not everyone is convinced that the human physique is the ideal form for a robot. Amazon spokesperson Xavier Van Chau told Fortune that while the e-commerce giant sees promise in the humanoid form factor, it hasn’t yet determined if it will use them long-term and also wants to test other types of robots, perhaps those that move with wheels instead of legs.

One humanoid skeptic is Brad Porter, the former vice president of robotics at Amazon. According to Porter, there’s a fundamental problem with creating a robot capable of operating autonomously in different settings: There’s not enough data to train AI models to safely control the robots.

“We don’t have the equivalent of the internet where everyone just pumped all text onto the internet over the last 20 years,” he says, referring to the data that generative AI products like ChatGPT have been trained on. And humanoid robots present a whole new set of risks.

“If ChatGPT throws an off-color joke every once in a while, it’s not really a problem, right?” he says rhetorically. “But if a robot throws an off-color middle finger or drops something, or glitches while it’s in an elevator with someone—those things can’t happen.”

Porter isn’t exactly a neutral observer. His startup Cobot is developing robots that use wheels instead of legs—a design he says is less costly and more practical for many tasks. A “swerve drive” allows the robot to move in any direction, while “multifunctional” arms can lift and grasp everything from boxes to trays. The company hasn’t announced any customers, but says its robots should be able to eventually work in settings ranging from manufacturing and fulfillment facilities to hospitals and stadiums. Among its investors is Amazon founder Bezos.

Whatever shape these robots ultimately take, the question remains of what happens to human jobs as robot use increases. Agility’s Johnson says Digit is taking on tasks humans don’t want or that an aging workforce can’t or shouldn’t be doing. Figure’s Adcock is more fatalistic. Technological advancements, whether it’s the creation of a dishwasher or a human-mimicking robot, are inevitable: “It’s basically what’s been happening for two centuries.”

This article appears in the October/November 2024 issue of Fortune with the headline “Meet your new coworker, the humanoid.”

More from the October/November issue of Fortune:

–Intel’s years of missteps leave it fighting for survival in the Nvidia-dominated AI era
–How the election broke Silicon Valley
–Where Silicon Valley is spending its millions in political donations, charted
–How GM CEO Mary Barra is transforming the auto giant for the EV future

Elon Musk, Jeff Bezos, and the robot revolution to end hard work