Diamonds are simply NFTs of the real life: worthless coupons that only prove that you've wasted a few tens of thousand dollars. They prove your social status. The battle for purity or the origin is a distraction. For the same reason, diamonds as a gift make sense only if they are expensive.

Agree, though it should be noted that diamonds are far from the only things like this - other questionably useful social status symbols include "luxury" fashion (low quality made in low wage countries...), or even just having the latest iPhone