> Abused children are taken away from their parents, but artefact are to simply be given back to whatever state has jurisdiction over some area they were in way back?

The reason why children are protected from abusive parents, is because they are protected by human right laws. A child is legally entitled to an upbringing safe from abuse, so a state is obligated to remove children from abusive housrholds.

Of course antiquities aren't people so they don't have any human rights. That is why it's stupid to compare artifacts to abused children.