Also: https://www.the-scientist.com/news-opinion/ferret-study-rein...

Even early on with the Diamond Princess you've seen wide spread of the virus despite passengers being largely confined to their cabins. There were multiple other examples.

We also know the Delta variant is more infectious.

I'm not saying distancing doesn't work. Even if you assume the virus is spread in the indoors air it's not a terrible bad assumptions to think that a person emitting virus continuously will have a higher concentration of virus in their immediate vicinity. So sure, it's layers of defense. The mask is also about limiting the emissions in the first place and distancing indoors is not always practical in public busy spaces.

But sure. It is not settled science. Science takes time. If your point is that we don't understand exactly what happens then sure, but we rarely do for anything in this field anyways.

but yes, viral concentration is higher near an infected person, but it falls off rapidly (to something like the 3rd power iirc) with distance and time, especially the latter of which being why incidental exposure in public places is unlikely to be material. it's also something a small minority of people have at a given time (on average less than 1% of those around you). it's mainly socializing for extended periods of time where masks can potentially help reduce infection (that's when we're also most likely to let our guard down).

i'd go so far as to posit that sociability (via variables like social graph size/breadth) is likely more correlated to infection than (the lack of) mask usage.