Without proven medical benefits derived from valid double-blind statistical studies (typically taking years)...
If you think they can't block the virus droplets, then you can't believe they somehow block much smaller gas particles like CO2 or O2.
There is ample direct evidence that mask wearing decreases transmission potential significantly, read the studies in the OP that started this thread - especially Argonne National Labs Study. We don't have time for years of double-blind testing nor do we need that. Its common sense, lower transmission = fewer cases. And there's also a strong logical correlation between societies with high mask wearing rates and low infection rates. We're now up to 29 states with mask mandates from both deep Red and Blue Governors, and many more in localities within the remaining states. Nobody should dare go into businesses in these small tourist towns like Lone Pine without a mask. Not only is it illegal, you have no right to put those people at risk and jeopardize the opening for the rest of us who can manage to wear a mask.
Goldman Sachs did a study on this topic and concluded that a national mask mandate would save the US economy about 5% GDP reduction that we're seeing from closures. This translates into about $1 TRILLION of economic activity, which equals about $3,000 for every American man, woman and child. We can't afford NOT to mandate masks where appropriate.
Whether or not masks are needed on trails, that's a different question and the point of this thread. I'm not seeing anyone argue strongly that they should be required under typical hiking circumstances, but they surely won't hurt anybody.
Edit: And you will get the boot out of the Portal Store if you don't wear a mask there either.
