[simianparrot]

Nurses and doctors wear masks to protect the patient from their own moisture droplets which may contain contaminants when breathing or talking. Same with dentists.

Do note they don’t wear N95 masks so they can’t filter smaller particles like viruses. It’s just to protect you from their saliva and breath droplets and spreading larger bacteria.

N95 masks are fairly effective if worn precisely and close fitting, but barely anyone used those because they are harder to breathe in.

A cloth mask or thin medical mask does practically nothing except protect others from larger droplets.