Sure but it’s all about quantifying that accurately so that it can be compared to for example better building ventilation. If, hypothetically, better ventilation had 100x the effect of mask wearing, then focusing attention on masks would be counter productive no? Make no mistake I’m pro mask but mostly for psychological, ethical and economic reasons. I feel their benefits in terms of personal protection are vastly overstated, often in bad faith by those with a desire to impact other people’s behavior albeit with the best of intentions.