I feel like "why not" is not a sufficient answer, especially when trying to explain a single object. The pharaohs were buried with everything, including people, so that's not a great analogy.
> Archaeologists have recovered dodecahedrons from the graves of men and women, in coin hoards and even in refuse heaps, so a blanket explanation for their use has not been found.
There's no indication these were the only things in graves that I can see.
