Masks Don't Work: A Review of Science Relevant to COVID-19 Social PolicyHere are key anchor points to the extensive scientific literature that establishes that wearing surgical masks and respirators (e.g., "N95") does not reduce the risk of contracting a verified illness:
Jacobs, J. L. et al. (2009) "Use of surgical face masks to reduce the incidence of the common cold among health care workers in Japan: A randomized controlled trial", American Journal of Infection Control, Volume 37, Issue 5, 417 - 419. https://www.ncbi.nlm.nih.gov/pubmed/19216002
N95-masked health-care workers (HCW) were significantly more likely to experience headaches. Face mask use in HCW was not demonstrated to provide benefit in terms of cold symptoms or getting colds.
More RCT studies at the link. The "weave" in N-95s is also not small enough to exclude viruses. It is designed to exclude bacteria from entering wounds being treated by medical personnel.
That study and 66 other studies are cited here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6993921/ Their conclusion is that masks work. Their critique of Jacobs is that it was "underpowered". You need to look at all the science, not just the science you agree with.