Many companies will need to reach a boiling point before they embrace remote work because doing so means moving away from the 9-to-5 model that’s been the status quo for generations. But, as Upwork CEO Stephane Kasriel told CNBC, it’s an unsustainable model that risks leading companies to a major crisis.

In “The future of jobs won’t be about 9-to-5 office hours, as power shifts to millennial leaders,” Kasriel explains why the concept of the workplace is quickly dying and the shift that’s coming in its wake:

“You can’t have a world in which 90 percent of a country is struggling because there aren’t jobs where they are. Nor can you have a world in which people all have to move to where the jobs are.

That’s why responsible leaders should get ahead of the remote work trend. There’s been gradual increasing pain, but there will be a major crisis. It’s just a matter of time. And the companies that wake up first will be the ones left standing.”

Online work is one factor that’s influencing the future of work: The number of U.S. freelancers who found projects online increased from 42 percent to 64 percent in five years, according to Freelancing in America. But Kasriel said it’s younger generations who will force the tipping point.

“Younger generations will see the trade-offs in quality of life and think traditional models are ridiculous,” he said. “As [they] take management reins, remote-work and flexible-work models will just be the norm to them. They’ll hire more remote people and empower their teams to work that way.”

According to Kasriel, established Fortune 500 corporations are most at risk: the lifespan of a Fortune 500 company has dropped from 75 years when the list first came out in 1955 to just 15 years today. In contrast, younger companies are often smaller, more agile, and able to adapt. Many of today’s startups build distributed teams from Day 1.

“The single most effective change a company can make is to take a remote-friendly approach,” he suggested. “Don’t just tolerate remote team members as add-ons. Assume everyone is or may be remote at any time. Kill conference calls. Prefer video calls. And on video calls, allow the remote folks to interrupt.”

Click here to read Kasriel’s full comments in this in-depth Q&A with CNBC >>