I mean that a lot of circumstances, having a picture/scan/copy only slightly diminishes the loss if the object is destroyed, and the existence of 3D scans etc shouldn't be confused with preservation of the original.

Obviously, take pictures and make 3D scans of everything! It's a great way to make unique objects available (to some extent) across the globe. But they're more aids to study than actual backups. Objects haven't been "saved" by being scanned; they're saved when they're actually preserved. A 3D scan of the Buddhas of Bamiyan would have only kinda sorta have ameliorated their loss.