More recent data strongly suggests that even people with no symptoms at low risk who have been sheltering in place should be wearing masks in public. I read an article over the weekend (which I unfortunately can't find now, although I found some similar ones) that described people on a plane with an infected passenger-- the rate of infection for healthy people wearing masks was literally zero, while those without masks was like 40%. I can't verify this now, but I have turned up a lot of articles describing how the official advice has changed on this.
I have a friend in a mid-size midwestern town in the U.S. whose mayor just put out a bulletin advising that everyone wear masks.
Similarly, there's at least one study out of China related to this recent outbreak showing the infection rate of the front line staff in hospitals (who were given N95 respirators) as zero, while the infection rate among other departments (radiology, etc) which were not wearing masks as much higher. That despite them calculating the front line staff having ~700% more exposure to the virus.
I know we want to study and confirm everything, but it seems like a real no-brainer that wearing a mask that filters droplets would reduce your disk of infection from an airborne virus generally spread via droplets.
And we're not talking about this in a hospital context, simply as harm reduction. As long as respirators are not an option for most of the general public due to supply issues, etc, then anything which reduces the infection rate is /better than nothing/, even if it isn't perfect.
I think you and others are making a lot of assumptions here - outside a hospital setting with trained staff and fitted masks to keep out virus-saturated air other vectors may be far more important.
There are reasons health experts around the world have not bothered to recommend general wearing of masks before other measures. Most people don't have the discipline to wear masks properly, not touch them, sterilise them, clean masks and all their clothes when they get in etc.
I have a friend in a mid-size midwestern town in the U.S. whose mayor just put out a bulletin advising that everyone wear masks.