How masks work

JAMA review of the Cochrane “study”

looks deeply at observational studies 

Well-designed observational studies have demonstrated the association of mask use with reduced transmission of SARS-CoV-2 in community settings, and rigorous evaluations of mask mandates have found substantial protection. Disagreement about whether face masks reduce the spread of SARS-CoV-2 has been exacerbated by a focus on randomized trials, which are limited in number, scope, and statistical power. Many effective public health policies have never been assessed in randomized clinical trials; such trials are not the gold standard of evidence for the efficacy of all interventions. Masking in the community to reduce the spread of SARS-CoV-2 is supported by robust evidence from diverse settings and populations. Data on the epidemiologic, environmental, and mask design parameters that influence the effectiveness of masking provide insights on when and how masks should be used to prevent transmission.

…

Robust available data support the use of face masks in community settings to reduce transmission of SARS-CoV-2 and should inform future responses to epidemics and pandemics caused by respiratory viruses.

how properly fitted respirators protect you 

One of the issues is that there are different types of masks that are designed for different purposes. Cloth masks and the common blue earloop procedure masks were never designed to protect people from airborne pathogens that hang in the air for extended periods of time