I’m surprised why they don’t just move it back to their own country and put it in a safe in Netherland.
It's also easier to sell in certain markets, such as London.
I wouldn't call that almost half, it used to be about half before the move (NY at 31.3, 19.7 in Canada).
In the olden days, the local lords would marry their children together, to create familial groups and ensure that for the forseeable future the local areas would not have a conflict. Modern democracies don't have such valuable family members, we use valuable objects instead.