"You have to have scale in order to address these problems," Kelly said of the company's large scale. Facebook can now "invest heavily in AI and machine learning."
Kelly, a Facebook shareholder, was an early leader of the social media giant. He worked at Facebook from 2004 to 2009 as Facebook's chief privacy officer and was its first general counsel.
Facebook released its third Community Standards Report on Thursday, in which CEO Mark Zuckerberg noted similar claims on privacy, saying breaking up the company would hurt its efforts to combat misinformation and policy-violating content.
"The amount of our budget that goes toward our safety systems is greater than Twitter's whole revenue this year," Zuckerberg said. "We're able to do things that I think are just not possible for other folks to do."
Kelly has spoken out in the past against breaking the company up. On May 13 he told "Squawk Box" that it's "not clear that Facebook has a monopoly in any relevant market."
"While it leads social networking, it's not overhauling marketing, telecommunications, messaging or online advertising, which are all defined antitrust markets," he added.
Facebook launched the Community Standards Report last May as a way to promote transparency, following the Cambridge Analytica scandal. It's the first report since Zuckerberg announced the company would change its products to focus more on private communication.
Several other former Facebook executives have come out against the company. In early May, Facebook co-founder Chris Hughes wrote an op-ed for The New York Times, calling on regulators to break up the tech giant. Other influential ex-Facebook insiders turned critics include former President Sean Parker, former Vice President Chamath Palihapitiya and early investor Roger McNamee.