That study is about the benefit of wearing surgical masks "in a setting where masks were uncommon and not among recommended public health measures"--thus answer

That study is about the benefit of wearing surgical masks "in a setting where masks were uncommon and not among recommended public health measures"--thus answering the question "do surgical masks protect the wearer." Surgical masks are thought to have a relatively limited benefit for the wearer, so this isn't surprising. However, https://www.nature.com/articles/d41586-021-02457-y https://www.nature.com/articles/d41586-021-02457-y demonstrates clearly that in a randomized controlled trial where surgical masks are distributed to a whole community, there was a statistically significant reduction in cases: "The decrease was a modest 9%, but the researchers suggest that the true risk reduction is probably much greater, in part because they did no SARS-CoV-2 testing of people without symptoms or whose symptoms did not meet the World Health Organization’s definition of the disease." There's certainly more to learn here, of course.