Essentially nobody is saying that it will stop you completely spreading The Joker Abbey Road signature shirt it just lessens the spread a little. But spread that across the whole population and it’s a big difference. From what I’ve read it’s more about reducing the distance a cough or sneeze goes in terms of droplets than saying it’ll seal your virus in. If you spray some water from a squirt bottle into the air in front of you, versus holding a piece of kitchen. Paper you’ll notice the difference between the dispersal. Every thing you are saying is right. I get the minimising of risk. By the time however everyone finishes their daily business they will have touched their face dozens of times increasing the infection.
So with the two metre distance rules and the masks The Joker Abbey Road signature shirt the droplets shouldn’t be as contagious if everyone has a mask. Nobody is saying it’s perfect and obviously the tighter the weave and fabric the better it is but even a makeshift mask achieves the basic lessening of spread through absorbing some of the velocity behind the sneeze/cough of someone infected. On the internet there are good videos of masks made from kitchen roll and elastic bands which take a few minutes to make. A big roll of kitchen paper will last ages and is not that expensive neither are elastic bands.