"But, wealth! If we all work less, we’ll be poorer, right? Because the total cash output of the economy is a (weird, nonlinear) function of the amount of work that gets put in."

In the previous sentence or so, there was talk about margins of healthcare, which have disappeared. These margins don't exist without more work.

Maybe it is rather that we are working with more things with less effort, rather than doing few things well.

Also cash and work have some correlation, but I think there is higher more profound correlation with work and total amount of products such as roads and buildings. Cash rarely stays in bank accounts but circulates and randomly spawns service and concrete products.

Everyone should work, all the time, to leave this a better place than we found it. And there is still much work to do.