And what you are seeing today is a distinct mix of using mass-party systems, while using monarchies that formed from Aristocrats. ;)
"Constitutional Monarchy" is just a watered down version of what I define as a "True Monarch", and given the fact that England is notoriously renowned for its Imperialistic Routes globally, from all over Africa, India, Asia, Europe, and frankly even the United States, considering our nation's founded Routes are based in origin from Great Britain, I wouldn't say there is anything to "Benefit" from a Monarch, but the whole "constitutional monarch" example, could easily be aligned with the equivalency of China's form of Communism, which isn't direct Communism, but contains aspects of Dictatorships, Communism, Totalitarianism, et al.
There is no Place for Kings and Queens in society today, sorry to say.
We can take a look at a period of time though where Monarch's ruled the land, and that would be the only other Era I would live in (Hellenistic Era) with Alexander the Great, and frankly, as advanced as we were back then, I would still choose to live in this Era where Monarchs do not rule the land in which we are governed.
I also really recommend you reading about what "Executives Orders" are "Article 2", and everything else in between that the President has full capabilities of doing so.
it is frankly a mere choice that congress has to be involved because of our laws are governed.
Anything that is in question goes to the Supreme Court, and with a 3:2 ruling of Republicans anything can be deemed as constitutional ;) you need to recognize there is a de-balance of power within our system of Congress, House, Supreme, WH and everything in-between