The Yale model that you pile onto illiquid investments to make seemingly  higher returns is being tested and my guess is that in the long term it would be worse than just sticking with a mix of public markets and a little bit of privates.

Private equity returns were good when there were limited investors and players but  US endowments took this as some magic formula and proved that they are also momentum investors- in this case playing the momentum of buying more and more into privates as if that is free money.