An artifact can be in a museum if, the person that owns the artifact says it's okay. Artifacts don't belong in a museum if the rightful owner says no, because what if that artifact is a hand down? Then what? Ruin family traditions, so they can't pass down their priceless belongings?
Some reasons why I don't think a special valuable artifact that belongs to a family is not belong in the museum are... honestly for one I thought of it like the pink panther movie, so I'm relating what might happen to an artifact to pink panther, like how they stole the pink Jewelry And they made a replica because the other one has been stolen. But yet again I do think some artifacts should be in museums because The Iceman for example how would you be able to keep the Iceman from thawing and rotting. You could also have your artifact in a local museum with your family name on it.
I think keeping the artifacts in a museum is a good way to keep it safe, unlike if you have it in your house it's not that safe because a burglar can get it easily. I am in between if people's artifacts should be in museums or should they be with the rightful owner.