So your argument is that the risk to the average American is low from COVID? Why do we have 300,000 cases then? Why are 1000 people dying a day? That's already 0.1% of the population, and most of them in the past week!
I would much rather overdo my PPE than underdo it. Overdoing it just costs me a little time, underdoing it costs lives and injury.
If you want to see what it takes to have a hospital where no one gets infected, this is instructive. https://youtu.be/9HsGqQCLzLU
I can imagine so many other more likely reasons for those deaths than face shield usage.