The problem is that you have governments like the Taliban in Afghanistan, pre-9/11, destroying ancient statues, trying to erase the history they don’t agree with.
Instead of returning stolen antiquities, countries that are currently in possession of them should be required to send an equivalent value of their own country’s treasure to be displayed in the victim country’s museums.
Imagine having to go to Egypt to see the crown jewels of England.
Awesome! Now do it to keep the cops from being able to force you to unlock your phone under duress.