You guys are way too interested to grab onto anything for this debate making it way to easy to question it.
The OP study...
Background Containment of the COVID-19 pandemic requires evidence-based strategies to reduce transmission. Because COVID-19 can spread via respired droplets, many states have mandated mask use in public settings. Randomized control trials have not clearly demonstrated mask efficacy against...
www.medrxiv.org
And at the top...
"This article is a preprint and has not been certified by peer review [what does this mean?]. It reports new medical research that has yet to be evaluated and so should not be used to guide clinical practice."
The only method deployed...
"We calculated total COVID-19 case growth and mask use for the continental United States with data from the Centers for Disease Control and Prevention and Institute for Health Metrics and Evaluation. We estimated post-mask mandate case growth in non-mandate states using median issuance dates of neighboring states with mandates."
(note the word estimated)
The OP study is nothing more than a mathematical study.
The MIT study...
And at the top...
"Edited by Renyi Zhang, Texas A&M University, College Station, TX, and accepted by Editorial Board Member John H. Seinfeld March 3, 2021 (received for review September 9, 2020)"
(Received for review is not the same as reviewed, thus not peer reviewed.)
Some (not even all) of the most important aspects and conclusions of the study, that the OP brought into this discussion, and nullified the first study. Making me question if the OP bothered to read either one.
"In both examples, the benefit of face masks is immediately apparent." (p8)
"While official quarantine guidelines emphasize the importance of isolating infected persons, our study makes clear the importance of isolating and clearing infected indoor air." (p8)
"Finally, we stress that our guideline is based on the average concentration of aerosols within the room. For every region of enhanced airborne pathogen concentration, there is necessarily a region of reduced concentration and lower transmission risk elsewhere in the room." (p10)
"Above all, our study makes clear the inadequacy of the SixFoot Rule in mitigating indoor airborne disease transmission and offers a rational, physically informed alternative for managing life in the time of COVID-19." (p11)
As in put on a mask, limit the number of people in an indoor area, and clean the place upon detection of contamination. The study actually mentions the number of people in a room, not the distance between them. Meaning one rule alone out of context is not enough, the true point of the study.
Said another way, treat the pandemic as a pandemic and quit coming up with useless shit to try to make a political argument devoid of what either study really means.