Thanks for posting the vid on mask wearing Currawong. But it does not tell the whole story.
The video shows excellent footage of how masks stifle the airflow. There is no debate as to whether a mask slows down and blocks the airflow of the breath...of course it does.
However there is more to consider than just airflow.
The strict scientific studies on the effectiveness of masks show conflicting results except for masks worn in professional medical settings. In other words, we just don’t know if widespread mask wearing by the general population will makes things better .....or worse.
A big problem is that masks should only be touched twice, once when putting on and once when taking off. Most people constantly touch their masks, and then touch other things, potentially spreading the virus even more than if they hadn’t worn the mask.
The video below shows two Professors talking about masks and the need for evidence based decision making. They don’t advocate mask wearing based on the available scientific studies.