> Even a low percent gain over the long term is very, very difficult.

In the words of those Screen Rants pitch meeting skits: "It'll be easy, barely an inconvenience!"

The easiest and most surefire form of investment out there is in land. There's a finite amount of it, so while on local scales values will fluctuate, on an aggregate scale the value of one's total land holdings will increase indefinitely as demand increases (which it will, both from a growing global population and a growing global economy). Land ain't especially liquid, but on long-term scales that ain't really a problem.

Until we as a society pull some moves out of the Georgist playbook and tax land value, the rich will always be motivated to consolidate that wealth into land control, and will be able to hold onto that wealth at the expense of everyone else.

You can't tell that investing is hard by how much endowment managers are paid. Convincing people you have the secret investing sauce is the most important skill of an endowment manager. All claim they can beat investing in index funds but there is no evidence they can.