At the same time, thanks to AI, this era will see some of the world's most difficult problems solved, particularly around health care, she said.
And for those worried about the so-called "singularity," when AI takes control of itself and creates runaway technological advances – that's still "decades and decades away."
"We know cause we're building this stuff," Rometty said. "It is far away."
Benioff got Rometty to discuss her early career, starting as an engineer in the auto industry, before her 36-year stint at IBM began.
Asked if she thought she would become CEO of this "legendary company" when she first joined Big Blue, she responded, "of course not," then countered, "Did you think you were going to run Salesforce?"
"Well, when I started it I did," was Benioff's reply, earning some laughs from the audience.
Working on trucks and buses provided an early lesson to Rometty in the difference between a job and career. She realized she needed a change, and her husband suggested she apply to IBM, where his friend's father worked and could make an introduction.
Rometty's knowledge in converting banks to Burroughs Corporation equipment helped land the job. That road led Rometty to become the ninth CEO of the 106-year-old company.
The main lesson she's learned in that time: "you have to be willing to change everything about yourself but your core values."
— Salesforce (@salesforce) November 8, 2017
Benioff noted that while technologies themselves aren't good or bad, there have been a lot of stories of late about how "some of these big companies, their technology got out of control," he said, especially "around elections."
"We saw them used in some unexpected ways," he said in a reference to Twitter and Facebook being manipulated by the Russian government in an attempt to sway public opinion in the U.S. election.
Rometty said that as a technology executive, "I don’t think you can turn your back on any of that."
Other emerging technologies also have dark sides that often are unexpected, she added.
IBM is making breakthroughs in quantum computing, and that technology one day will solve problems today's computers cannot. Great advances like discovering new drugs, risk modeling, logistics will come out of that.
But within several years, quantum computers might break almost all forms of encryption currently available, she said.
"While working to build it, we're working on the antidote," she said.
IBM won't reveal what that "antidote" to quantum code-breaking will look like, but she assured the audience her company won't release something that powerful until it knows it can control its negative consequences.