After spending the 10 minutes to look at the studies that Rancourt claims say something that they don't, I did a little research on him. Rancourt is a piece of work, fired from his teaching position, sued for defamation and lost.
But it also led me to this lengthy rebuttal of his piece which tears apart Rancourt's argument point by point.
https://davidkylejohnson.wordpress....enis-rancourts-argument-that-masks-dont-work/
I read the article that you posted. The author did a lot of damage to the credibility of his article by spending the first few minutes of my time doing a political hit on Rancourt, which of course shows that the content of this "scientific" article is EXTREMELY influenced by his political bias and hatred for Rancourt. This id very bad news for interpreting science.
The biggest problem with the hit piece that you posted is that it simply does not state or prove that masks "stop the transmission of viruses" like Rancourt's article states. In fact, the hit piece states in his mask presentation that "So, if you are in a room with a non-masked infected person, you are pretty likely to be infected even if you are wearing a cloth mask". At best, he conflated "stopping viruses" with "helping reduce" transmission. Nowhere does he say that masks do in fact stop transmission of viruses. He actually gave Rancourt's article more credibility when he spilled the beans about how hard it is to stop the virus after droplets evaporate and the tiny droplet nuclei goes floating off.