If you view the humans actually producing stuff as human capital, which many economists have done, then keeping that (human) capital in decent enough form by allowing it to have access to decent enough healthcare is a logical step forward.

We could then go a step or two forward and posit that a sick populace means a sick consumer class means reduced demand for goods that generate growth, but those are just details.

nobody does. which is ironic since root for capital is latin for head count.