I work at an archive. We have hundreds of thousands of photographs that would be super cool to publish in different contexts, but we can't, because
This is just how it is. In one hundred years' time (or less, obviously, with older photos) we can publish because the copyright has expired and the people depicted are dead, but right now we just have to put the photo away. Same thing if our customers want copies of the photos. It depends on their purpose, but there is always a chance that we have to say sorry, we can't because we don't have the rights, and we can't gain the rights.