Private equity is vs not going public in the first place though. Private equity is also the wrong measure because there's good private equity and bad private equity, and we most commonly hear about bad private equity. Eg Toys'R'us. Typically when buying a company, in order to but the company in the first place, PE saddles the company up with debt in order to make the purchase in the first place (which is bananas in the first if you think about it). So then the distressed company now has additional debt payments to make. Making their already distressed situation even worse. Now, the theory is that PE is able to make the company more "efficient" with their PE know-how, and sometimes they do. There's no time machine too go back and undo the PE purchase of Toys'r'us and see what would have actually unfolded, but what we can say is having to make additional debt payments hastened their demise.

So it's true PE taking a company private has a high failure rate as far as the continuation of the company, the question is if the goal of PE is for the company to continue in the first place, or if that gets in the way of them extracting as money as possible as fast as possible. So 50% is certainly a statistic, but not useful for comparison, especially if we're looking at a private company staying private.