Because they do not work unless you are clean shaven;
because you are recirculating an virus you may have and concentrating it;
because they only are good for 4 hours and washing destroys the effectiveness of the filter;
because they are generally a waste of money unless you are in a clinical environment.
And all this ‘safety’ and ‘sterility’ degrades your immune system.
Why do you assume Garry is infected - the mask will not prevent you from catching it?
If you are wearing a mask, I assume you are infected.
In less than 55 sec .... Wild Bill “Bullet of Truth”
Dealing With Mask Meanies [Wild Bill for America]
https://www.youtube.com/watch?v=X1V3Gd_qsaM