Did you read the study? I just did...because this is a boring fight card. The sample size is too low to have population-level implications and it's not statistically significant. The Federalist article you originally cited also misinterprets the study, which isn't set up to compare the efficacy of mask usage vs. non-mask usage in the slightest. If the cohort selections didn't give that away, it's obvious that you've never looked through a study before today. Given the difficulty of gauging adherence in a study population, as indicated in the CDC study you cited, you'd be better off looking at population-level metrics where entire cities/states deployed mask mandates and see how they compare to states that did not. Low and behold, dozens of studies have done just that and shown convincingly that masks are effective. Even if that warning label is legitimate, which it might be since fabric and mask design are a factor in efficacy, it means nothing. There are labels on just about everything in California and that doesn't mean they serve any purpose other than preventing a potential lawsuit.
