Clearly unpopular opinion but I disagree. Well aside from the slim it down part, that would be wise to do pre-emptively. I'm not for returning treasures to shitholes yet. But if it should be done, it should be based on the will of the majority, and logic and reason, not appeals to emotion. There are way more pragmatic and productive ways repatriation is appropriate. Pretty sure 1/3rd of Pakistan being underwater is a more pressing issue than diamonds.
As for the strawmen replies, pointing out the fact the royals don't actually cost money isn't the same as suggesting any country that isn't a monarchy should inbreed some royals and switch to a monarchy. tf... Getting one (a royal family) is not quite the same as getting rid of one. No idea why making Boris Johnson or some upcoming populist head of state, or giving a football to launch nukes to a TV personality / con man sounds so much better than a lame duck raised to be nothing but a lame duck that fills a flaw in democracy itself. Complaints should include a better alternative. But then, it's a topic that deserves a dialectic approach, which is pretty much dead and why the world is such a shit show. People and their fragile pretentious egos and snowflake feelings, it'll be the end of us all. Except a few, who'll bash the brains out of anyone who dares to come up with the stupid fallacies that endangers the species and the entire planet. I had some hopes Trump would take it so far it would be the end of illogical dumb shit... then maybe covid would kill all the dumbfucks. But of course, that was naive, bullshit is only bullshit when it comes from political opponents, not when you excrete it yourself.