We do know that masks significantly lower the spread, and while not completely protecting you against getting Covid, it will give you a Significantly better chance of living
Yeah, its not perfect protection (no one ever claimed it was), but it significantly lowers the spread enough to be worthwhile esp. in conjunction with other common-sense social distancing measures, hygiene, etc.
I didn't know that one: but it makes sense, fewer virus particles making it into your body to cause an infection suggests a less-intense infection and greater possibility of survival.