The effectiveness of masking has been proven to be not as strong as has been promoted
I think proven is a strong word, especially when they acknowledge themselves things like:
Evidence is limited by imprecision and heterogeneity for these subjective outcomes.
We are very uncertain on the effects of N95/P2 respirators
Wearing masks in the community probably makes little or no difference to the outcome of influenza‐like illness (ILI)/COVID‐19 like illness compared to not wearing masks (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.84 to 1.09; 9 trials, 276,917 participants
Harms were poorly measured and reported, but discomfort wearing medical/surgical masks or N95/P2 respirators was mentioned in several studies (very low‐certainty evidence).
while forgetting it was not about the outcome of disease progression, it was actually about reducing the rapidity of progression of transmission within the community or the R value. I don't think anyone doubted that over time everyone would get it. I for one have said its a almost a certainty that I'd get it (and I did).
Using "proven" is like saying "all" ... if I were to say "all Americans are unable to read properly" it would be improper and wrong.
Its the correct and accurate use of words which distinguishes science and veracity from hype or marketing or pushing an agenda.
I wonder if you're watching a particular YouTube channel by a well known educator
The Authors conclusions sums it up
The high risk of bias in the trials, variation in outcome measurement, and relatively low adherence with the interventions during the studies hampers drawing firm conclusions.