More than 40% of CEOs plan to cut junior roles over the next one to two years and shift the composition of their workforce toward mid-level or senior positions, while only 17% plan to make junior roles a bigger part of the mix, according to a global survey by Oliver Wyman. The numbers are essentially flipped from just a year ago.

“I think the junior level is definitely finding it harder now to enter the workforce,” said John Romeo, who leads the consulting firm’s research arm, the Oliver Wyman Forum. “It’s those mid- and senior-level employees that CEOs are now looking at to drive productivity.”

That’s because of the types of tasks that AI agents are able to perform, from writing code at the level of a junior developer to evaluating sales leads. What the agents can’t do in many fields is make judgment calls using the insight that comes from on-the-job experience, according to labor experts.

Companies are saying, “I need someone who’s actually done this before because her experience, her wisdom, her critical thinking and the fact that she solved these problems makes her much more valuable,” said consultant and lecturer Ravin Jesuthasan, who has written multiple books on the future of work.

The Oliver Wyman survey results build on findings from a Harvard University study showing that firms adopting generative AI have significantly reduced junior-level positions, while keeping senior employment largely stable. Foregoing younger talent now in favor of AI agents comes with significant risks, though, as it may leave companies with a shortage of experienced workers in the future, according to Helen Leis, global head of leadership and change at Oliver Wyman.

To “have the mid-level people that can manage an agentic workforce, they need to learn the company and the job,” Leis said.

With that idea in mind, International Business Machines Corp. said in February that it plans to triple entry-level hiring in the US this year and will rewrite job descriptions for the AI era. IBM appears to be an outlier, though. A study from Stanford University in November found that young workers were 16% more likely to lose their jobs in the most AI-exposed fields.

But even if AI is tipping the scales in the job market toward older workers, it’s no guarantee of job security for them. “Firms’ commitment to workers is weaker and weaker,” said Teresa Ghilarducci, a labor economist at the New School.

In 2001, Fortune first convened the smartest people we know, bringing together CEOs and founders, builders and investors, thinkers and doers. Since then, Fortune Brainstorm Tech has been the place where bold ideas collide. From June 8–10, we will return to Aspen—where it all began—to mark 25 years of Brainstorm. Register now.