@trazor ,
you're getting mixed up.
We are to wear face coverings to protect others.
"Doctors/nurses" (your quote) wear them to protect themselves.
Two entirely differing purposes.
Nor gloves. Or coveralls and overboots.
Don't forget to go out in sacrificial undergarments too, and have them disposed of in a bio-secure manner.
Plus, if face coverings are effective, why would you want to (wear a face shield)?
Each extra level of PPE adds to your/their protection, are you still confused.