What is the ideal asset allocation?

[Jason Powell]

If you had a pot of money you have to invest that you needed to live off of for decades, how would you invest it? "Conventional wisdom", modern portfolio theory, and the typical asset allocation of high net worth individuals shows a balance between real estate, publicly traded stocks, private equity, and cash/fixed income.

How risky would it be to invest 100% in real estate? Could a prudent investor go all in on this asset class, assuming the investments were blended across the risk/return spectrum (i.e. some low LTV or debt free, some 1st lien loans, some higher LTV, etc)

I'm asking purely regarding a passive investing style, assuming no directly held real estate but rather only a syndication model as a LP. I'm also assuming one would still keep adequate cash on hand to cover emergencies and recessions where income may go down.