> Going full index is a great strategy for an individual person aged 20-50, but not a strategy for a pension fund which needs to continuously pay out.

It's OK for a person in their 70s that has a few million in the bank.

This person (CPPIB) has 780 billion and has a sustainability rating for 75 years.

$780 billion divided by 6 million current recipients is a little over $100,000, which is hardly comparable to your wealth retiree example.