Viruses are small. All filters are not created equal. Idiocy abounds. Our citizenry is downright ignorant about basic dimensions. The gap between the average citizen’s entry-level scientific literacy and that necessary to function in a semi-technical society is about one parsec.
Thankfully, we have American Thinker and Andrea Widburg on duty. https://www.americanthinker.com/blog/2020/09/the_cdc_director_has_doubled_down_on_masks_but_is_he_wrong.html