Masks (niqabs in Arabic) have occasional uses. From ceremonial masks to surgical masks to preventive masks, etc.
Masks are not a piece of clothing and cannot be regularly worn at public places and assemblies. Covering one’s identity could jeopardize other people’s security. Most importantly, covering one’s face and hands is not decreedin Koran /Islam. It is made up by some zealous Islamists and represents Islamic fundamentalism.