Comment by pm215

I think another aspect here is that museums don't have infinite display space. So if famous items X, Y and Z are on permanent display that's less space available for other, less famous but perhaps equally interesting, items that are stuck in storage. Rotating the famous items into storage doesn't mean the museum has blank walls for a year.

Arguably there's more educational value and more chance of a visitor serendipitously encountering something that speaks to them if the museum has a big set of prints rotated through, rather than a more static one. After all, even if you haven't ever seen an original of the Great Wave you almost certainly already know the image and it's likely already made most of the impact on you that it ever will...