Imagine being at the gas pump, and the person next to you sprays gasoline at you. A faceshield might keep your face from getting soaking wet, but if you smell the fumes, it hasn't prevented exposure to your sinuses or lungs.

Except you can't smell a virus.

For the most part, the virus is carried in the droplets, so if you protect yourself from the droplets, you're way ahead of the game.

I'm hoping Doctors aren't being hosed down with concentrated gallons of trillions and trillions of virus. PPEs aren't going to do much in that situation.

That isn't what a face shield is for and it won't protect you in that scenario.

It is exactly what it is for, to protect from droplets sprayed out of sick people. Particularly to keep it out of your eyes.