It makes no difference what the article is about. Masks are useless because hands are the prime vector. You can talk all day about washing your hands but no one can keep from touching their face, rubbing their eyes, nose or ears. And since this “article” is about asymptomatic carriers of the virus then washing your hands is 100% useless.
Actually what the article says is that it prevents as many particles from entering the atmosphere from asymptomatic people.
It apparently assumes symptomatic people aren’t out and about.
If all the infectious people wear masks, there will be fewer particles in the environment to get on your hands in the first place.