I don't think PE buyouts are the right comparison here; we're talking about companies that never go public versus the ones that do.

And, of course private companies fail at a much higher rate. The set of private companies includes every company that doesn't succeed to the point where it has the realistic choice to go public. Again: wrong comparison.

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.

Needing to maximize shareholder value is a myth. There is no law that requires you to do that - people like to use the idea as an excuse to do scummy business.

IPOs result in companies cutting corners and offering worse service so they can offer more benefits to rich stockholders this quarter, so they can cash out and burn the company to move on to the next one. Private companies plan for their existence 10 years down the road.

Why should anyone be entitled to stocks of a company?