I haven’t checked, but I suspect the return is less than they would have gotten just sticking the money in an S&P 500 index fund over the same 14 years. Still, the risk is lower.
And it's definitely not true on a risk adjusted or cash flow basis. Also these deals can be (and probably was) levered to levels which equity investments cannot. Borrow at SOFR+x% and earn on the spread between that value and 16%. Extremely profitable and uncommon carry trade