A more proper analogy: what if, for books from every different vendor, you had to get a separate bookcase (they won't fit in each others' bookcases), which coul

A more proper analogy: what if, for books from every different vendor, you had to get a separate bookcase (they won't fit in each others' bookcases), which could be removed from your house at their whim at any moment, taking along all the books in it with them?