Note sure this is a strong counter argument. It not that surprising that a system optimised in a certain direction has trouble accommodating operating modes it hasn’t optimised for.

As retirees. One explanation could be the lack of free time and resources over the course of their life prevented them from developing themselves enough to have something to do.

A small parallel is that (for me) a weekend is not enough to do much more than recover from the workweek. But two weeks off is enough to recover and then do some more things. Even then, it would take more time to do things of major significance.