It’s not cartoonishly incorrect, in fact it’s mostly correct. Healthcare workers wear masks mostly to protect their patients. They themselves may get some protection from splashing/spurting bodily or other fluids, but not from any airborne contaminants or infections.

> A. Masks were introduced into clinical practice at the beginning of the 20th century to protect patients from microorganisms being expelled from healthcare workers’ respiratory tracts during clinical procedures (Wilson, 2006).

https://www.nursingtimes.net/archive/when-should-staff-wear-...