> There are hundreds of studies. And, it’s pretty conclusive that masks have zero efficacy for stopping viral transmission

Could you link some?

What I have read seems to suggest otherwise, for example "Efficacy of face mask in preventing respiratory virus transmission: A systematic review and meta-analysis" [1]

Key conclusion: "Meta-analyses suggest that mask use provided a significant protective effect"

[1] https://pubmed.ncbi.nlm.nih.gov/32473312/