On one side: founders and investors grappling with the vertigo of an era where execution timelines have collapsed almost overnight. On the other: rank-and-file workers who aren’t afraid they’re moving too slowly—they’re afraid the whole machine is designed to replace them.

In a new video from Andreessen Horowitz, a16z cofounder and general partner Ben Horowitz told a by-now-familiar tale of the unfolding industrial revolution tied to artificial intelligence, describing an era in which the fundamental rules of competition have been rewritten so completely that pre-AI companies are playing a game they no longer understand. “If you keep looking at it like the old world, and it’s got completely different laws of physics, you are definitely going to die,” he told the audience at a16z’s Connect/Fintech conference in Park City, Utah. The window that once gave a strong software product 10 years of runway, then five years, he said, has now compressed to “maybe five weeks.” That vertigo—the fear of not moving fast enough—is what Horowitz calls founders’ AI anxiety.

That compressed timeline is producing what Horowitz described as a pervasive anxiety among founders—particularly those who built their companies before AI and now face a market that has structurally changed beneath them. The two competitive moats that software CEOs relied on for decades—the inability to throw money at a problem to catch up, and customer lock-in through switching costs—are both gone, Horowitz argued. “You can buy enough GPUs and solve basically anything in software,” he said. And as for lock-in: “It’s very easy to replicate the code. It’s very easy to move the data.” The SaaS apocalypse, in his telling, is not hype. It is arithmetic.

This is significant, coming from Horowitz, one of Silicon Valley’s most influential and respected figures. A rare combination of battle-tested operator and elite venture capitalist, Horowitz is practically mythologized in the Valley for his no-nonsense management philosophy. He is famously intolerant of excuses and victimhood — once publicly calling out “the crybabies of Silicon Valley” for not outworking their rivals. His thinking on management—particularly around wartime versus peacetime CEOs, the importance of candor, and making hard personnel decisions—is widely cited in startup circles as some of the most actionable leadership content ever produced. But what Horowitz is watching among founders—call it AI anxiety from above, the fear of not moving fast enough—is the mirror image of what’s happening on the ground inside the companies those founders run.

Fear of becoming obsolete

Workers aren’t afraid they’re moving too slowly. They’re afraid they’re becoming irrelevant altogether. Call it FOBO—the fear of becoming obsolete. Roughly half of American workers now name AI-driven job loss as one of their primary fears, a share that has nearly doubled in a single year, according to KPMG. Even more say AI will make the workplace feel less human. Unlike traditional job insecurity, FOBO isn’t about getting fired today—it’s about waking up one morning and finding that your skills no longer matter.

The behavioral consequence of FOBO is already showing up in the data. A new global survey of 3,750 executives and employees across 14 countries by WalkMe found that more than 54% of workers bypassed their company’s AI tools in the past 30 days and completed the work manually instead; another 33% haven’t used AI at all. Combined, roughly eight in 10 enterprise workers are either avoiding or actively rejecting the technology their employers are spending record sums to deploy, even as average digital transformation budgets rose 38% year over year to $54.2 million. WalkMe CEO Dan Adika previously told Fortune that the share of employees doing meaningful work with AI is “sub-10%.”

That resistance is not irrational. It is, as a new MIT FutureTech study suggests, “far less like a sudden catastrophe and far more like a slow, rising flood.” For workers, that is cold comfort. The flood is still approaching. It’s just moving at a pace that allows you to watch it approach. Workers watching Oracle and Block announce layoffs with AI cited as the rationale, are drawing conclusions that no training program is going to override.

The perverse irony, documented in the FOBO research, is that the fear itself accelerates the outcome workers dread most. Workers who resist AI adoption fall further behind peers leveraging the tools—in some cases by a factor of 10 or 20 to one in productivity.

Horowitz, for his part, is not pessimistic about where this lands. Invoking the Industrial Revolution—when more than 90% of Americans were farmers before virtually all of those jobs were automated away—he argued the pattern is consistent: Technology eliminates jobs people recognize and creates ones they cannot yet imagine. “The history of technology is things have always gotten better,” he said. “I think it’s very very likely to be way, way, way better for everybody.”

But he also let slip the premise that complicates that argument. “If you take a lot of these ideas to their logical conclusion,” he said, “then nothing is worth anything, because there are no people at companies. And if there are no people, who’s going to buy your software?” Still, he said that tech disruption has been much more “subtle” than that through history, and it will take time for this to play out, just as with previous disruptions.

The founders are anxious about the pace. The workers are anxious about purpose. The gap between those two anxieties is where the real disruption lives—and right now, almost no one is bridging it. Fewer than 19% of U.S. establishments have adopted AI, according to Goldman Sachs economists. The revolution Horowitz is racing toward has barely begun. The workers dreading it have already started to check out.

A16z did not respond to a request for comment.

For this story, Fortune journalists used generative AI as a research tool. An editor verified the accuracy of the information before publishing.