A better reason is that the Muslim rulers of Greece at that time were recycling ancient artwork into building materials. Those marbles survived because the British kept them out of Muslim hands.
I posted mine before I saw yours. I hope the Muslims won’t get their hands on them again.
The Venetians shelled the Parthenon and set off explosions in the ammo the Turks had stored in or near it, and the explosion did much of the damage.
The rest of the damage was done over a period of several generations by the British Museum, because the marbles looked dirty.
https://en.wikipedia.org/wiki/Elgin_Marbles