By the way: Why did WHO tell that masks won't help??
I believe this was a ploy to reduce the use of masks by non-medical civilians outside of hospitals. I think it was done because there was a severe shortage of masks. It was disingenuous. No one in Asia followed this advice. On the contrary, governments there insisted that everyone should wear a mask, and they took steps to manufacture and distribute them to all citizens. Especially washable cloth masks.
This is partly because wearing a mask is a normal, everyday thing to do in Asia. It is done partly to keep cold air from bothering you, like wearing a muffler.