Leon Black, Chairman, CEO and Director, Apollo Global Management, LLC, speaks at the Milken Institute's 21st Global Conference in Beverly Hills, California, May 1, 2018. Lucy Nicholson | Reuters

The fact that more public companies are being acquired by large global private equity firms is neither shocking nor problematic, at least according to the titans of private equity. It's hardly surprising that boards of formerly public companies elect to give private equity a chance, said Jonathan Sokoloff, managing partner of Leonard Green & Partners. "Our view is that we're a better model. We're a better model for governance. We don't have to deal with all the hassles of the public boards," Sokoloff told CNBC's Leslie Picker at the Milken Global Investment Conference last Tuesday. "You go to a private company board meeting: we get right down to the meat of the business, and we help the businesses and we're involved," he added. "It's a pretty dramatic shift that's going on, and the public equity markets are really losing share."

Other private equity managers on the panel echoed Sokoloff's comments. The panelists also included Apollo Global Management's Leon Black, Vista Equity Partners' Robert Smith and Brookfield Asset Management's Bruce Flatt. According to a Credit Suisse report published in 2017, the number of publicly traded U.S. companies has been cut in half over the past 20 years, falling to 3,671 from 7,322 in the two decades ending in 2016. While private equity buyouts can account for some of the drop in the number of public companies, some executives of companies such as Uber and Airbnb are simply electing to delay their IPOs. Their explanations for the delay have ranged from increased regulation in the public sphere to shareholder lawsuits and activist pressure. While notable in its own right, the decline in the number of public companies has been accompanied by a mass migration of capital into private equity as some of the world's largest pension funds remain strapped for reliable returns.