Like we said several times, masks provide some protection (decreased risk) for a healthy person, they don't protect from getting infected 100%.
No one ever said that mask is more effective on healthy person than on the infected one, I am not sure who you are arguing against. But it is the popular for some reason notion that a mask does not protect a healthy person at all that is plain false as has to go away.
https://www.npr.org/sections/health-shots/2020/03/14/8116090...
https://www.chemistryviews.org/details/news/10608438/How_Lon...
"The viruses remained detectable for up to 4 hours on copper, up to 24 hours on cardboard, and up to 3 days on plastic and stainless steel."
Different surfaces are, well, different.
And don't forget the social signal part; if everyone wears a mask all the time, then we don't know who actually considers themselves to be infectious. Whereas if just the infectious people wear masks, then we know who they are and can act appropriately (being grateful that they self-identified as infectious and kept the rest of us safer, for a start).
I think the point is that you have no idea whether you're healthy.
If ONLY sick people tend to wear masks then masks will make you a more visible target of fear and hate, which would lead people who are sick to not wear masks.
It's a much better idea to destigmatize the act of mask wearing so we can get larger coverage of sick people with mask s.
In Asia, the feeling is gratitude - thank you for wearing a mask and protecting me from your illness