[M T]

  For instance, if all the High School teachers were trained and ready to step into the job, they could have been deployed in March.

Hey, no! In our public high school district, teachers were responsible for planning and managing their classes via Zoom, Google Meet, with some shared time, some prep time, assignments, and grading time. They weren't just on vacation. The kids and their parents needed them.

Good point.  Not having kids in school, I forgot that teachers weren't really not working when the schools closed.

But the main point is to find some class of workers that are not in critical jobs and add a new task to their jobs.  Let's see,  park rangers, librarians, ...

[M T]

  For instance, if all the High School teachers were trained and ready to step into the job, they could have been deployed in March.

Hey, no! In our public high school district, teachers were responsible for planning and managing their classes via Zoom, Google Meet, with some shared time, some prep time, assignments, and grading time. They weren't just on vacation. The kids and their parents needed them.

Good point.  Not having kids in school, I forgot that teachers weren't really not working when the schools closed.

But the main point is to find some class of workers that are not in critical jobs and add a new task to their jobs.  Let's see,  park rangers, librarians, ...