I kind of get it but I also do not. If you are the survivor of a post-nuclear world, then what are the actual chances you get to meet another survivor? In that kind of world, not even seeds, banknotes or coffee is helpful anymore.
I suggest coffee still is, while admittedly more enjoyable in good company. But whatever, I see your point.
Indeed, coffee will be highly valued as it doesn't grow here and supply chains/routes will be devastated.