Western societies took advantage of multiple other societies to plunder their treasures. Those same societies didn't have the infrastructure and/or care to preserve these things themselves.
Not necessarily true- the majority of people don't know about 3-2-1 backup strategy and I've seen hundreds of "help! my { phone | SD card | computer } died and I lost all my family photos" posts
Western societies took advantage of multiple other societies to plunder their treasures. Those same societies didn't have the infrastructure and/or care to preserve these things themselves.
Sometimes two things can be true.