Masks don't work because Covid can be absorbed through the eyes. 6 feet doesn't work because sneezes and coughs travel further than that. This was never about "contagion", only control
Masks don’t work, primarily, because there is no seal for the exhaust, and even the best of them is of very limited effectiveness against viruses. The only PPE that would actually work are the “space suits” that I imagine medical staff wore in the covid wards, which also had positive air pressure. It goes far beyond the fact that it can be contracted through the eyes, which is certainly true.