Good points … not entirely accurate when it comes to the balance sheet (the funding of the British monarchy is ridiculously complicated), but you made a logical case (albeit one infused with sarcasm) and there is only one thing that I can say to refute it.
We yanks tossed off the crowns, thrones, lords, ladies, stones and scones nearly 250 years ago, and what have we to show for it?
Donald J. Trump sitting at the Resolution Desk (jolly good of you to give us that BTW) plotting to steal, besmirch, fondle or otherwise fuck over every damned thing on the planet.
If the goal was to trade up, I fear that we failed!