Here's your chance for a really big, long-lasting invention.
Walking around the neighborhood, I wear my mask dangling around my neck until someone draws near and then I place my mask over my mouth and nose until we have passed each other a safe distance. A lot of people do the same.
After this pandemic, I suspect that handshakes may never return. At a minimum, they will be less common.
So, perhaps we'll have a new gesture for greeting, something that conveys respect and wishes good health. A hand gesture that imitates putting on a mask? A hand across the face as if to guard it? Some modified Namaste gesture over the face? The mask may be gone, but the gesture to put it on as a show of respect for the health of another staying with us.
I'm not sure what such a gesture of greeting or respect might look like but given the persistence of handshakes for centuries, a greeting that replace it could be huge, could last for generations. Now that would be a social invention.