

That’s an argument against an executive branch of government, not an argument against a constitutional monarchy.
You could have (and many countries do) a parliamentary system like you describe without having a monarch figurehead.
The question I think OP is asking is: why have the monarch figurehead.
No matter where you live, AirBnB/VRBO can only make housing prices go up, never down. At best it’ll be neutral. It’s always taking inventory that might otherwise go to a local.