It's a lot harder for the virus to make it through two masks (the one on the sick person is the especially important one) and it seems if you don't get a exposed to a high enough viral load at the start, you don't get it nearly as bad.
I think universal mask wearing would bring R0 below 1, and the pandemic would end.
Costco requires a mask to shop in their stores (at least where I am.) If you don't have one, they will give you one (and an admonition to save it for the next visit.) I feel safer shopping there than any other store right now.