I know this is well known but still worth mentioning again I think. That the "regular" facemasks were primarily so asymptomatic people with covid would spread it less. 100% protection was never possible but anything to delay to spread so that not everybody was sick at the same time was necessary.
I think the global "everyone put on a mask" moment highlighted some large cultural differences.
My Asian friends understood that "not sharing germs" was as important as "not getting sick" mask compliance as much about being kind to others as to yourself. It also helps that lots of them were already socially accepting of masks due to climate, pollution and weather (or what ever you want to call dust out of Mongolia every year).
I think that there is an interesting corollary with PPE culture in general, one that has changed in my life time (safety glasses and seat belts). I think we saw a lot of that same behavior bleed out to normal people (who don't wear PPE at a day job) in action.
All in all there is a cultural aspects at play that are worth looking at.
