>I'll admit, monarchy has its strengths. it offers charismatic leadership, stability, and efficiency
Hm, now I want to play devil's advocate.
There are plenty of examples of republics long-lasting republics like Rome and city-states from Medieval period (particularly Venice).
I don't care what anyone here thinks about royal monarchy
>these liabilities are greatly magnified by the power of the Crown
A crown exists to be worn, with the monarch as the head of a body. The monarch and institution exist as one (or, at least, that is how I would prefer). A coronation oath as a promise to perform on public good.
It's unlikely it will be so bad for all if there is a little bit of corruption--even if it was a little bit of self-interest--because a monarch already has most to content himself and its only for the satisfaction for one person. Roughly speaking, that won't hurt as much on a large scale--those closest to the monarch, those trying to influence the monarch--they are more in danger than any ordinary people.
Also, a monarchy isn't necessarily all doing--although it is total--people will rule like subordinate households. It really doesn't take the most merit to do something as simple as rule over a nation--look at any head of state today and tell me that's not true, because they're idiots and they're still doing fine. He doesn't need the virtue of strength and big burly muscles--he doesn't need big intelligence either--simply put, it begins with extraordinary virtue, outside of that--his self-discipline is first for a monarch. This is like for any person--say that you get punished... It doesn't teach you to be a good person, by restriction, as much as coming to learn by your own understanding and knowledge. That is simple social reinforcement and the other is virtue.
Anyways, even with a bad guy, he can't go and get you everywhere at once. A monarch has that one advantage of its distance. Ordinary people minding their own business--they will be out of harms way with that kind of monarch for the vast majority...
But I don't really buy into this good king and bad king thing. It's often the case that it's both characteristics, good and bad, with a monarch (or just a really mediocre one). For example, take a leader who does something people here would consider good--he creates an ethnostate. That's going to be condemned harshly and labelled as tyranny from crybabies within and observers outside. And a multicultural paradise--that will be showered in praise for being the perfect love regime.
>in addition, the whole emphasis on bloodlines is a false doctrine, character and ability are not directly inherited
They do say like father, like son--but imo that's part of the appeal for dynastic monarchy in some ways. It is a preservation of the character and predecessor, but also the form. It actually does sometimes work to preserve the character of that person in some instances. And when it is like that--the benefit is that its following in the footsteps--a kind of wisdom of his lineage.
That is the main appeal to have emperors looking back at their grandfathers and saying, "I want to be great like him--I want to make my people great and proud like it was in his time." And when it isn't like that, you could say it is a welcome innovation to have a royal monarch bring a different character once in a while. But even with non-hereditary monarchs or leaders, they often look back to a great person or period and say that they want to bring things back to those golden days.
>the rule of law & constitutional supremacy have a tempering, stabilizing effect, providing a solid foundation amidst the chaos of vacillating majorities and administrations.
I'm not opposed to having laws, but I stress that laws could also have magnificent effects. Laws are capable of preserving and oppressing. It's often the case with the accumulation of laws--that an oligarchy lives, breaths, and moves through laws to restrict. That's how you find popular monarchs--usually, that an abundance of laws and a mess of regulations demands reform--it demands a monarch that could reform and pull these back... like you said, the check and balance of a clique like a multi-party system--too slow to adequately reform like this, you could say, but accumulate laws and regulations much faster in their conduct.
I tend to stress that monarchy has the potential to be an instrument of reform. Like I said, the wisdom of monarchs--there are general instances where the laws aren't always the answer and an absolutist approach is necessary. Like I said with the heirs--sometimes it is right that a monarch does this.
not the laws are bad--they benefit everyone, but this should be remembered
It's likewise important that the spirit of the monarch's reign should be preserved in those laws and leave room for the heart of them--leave room for mercy from their penalties.
>on that last point, I suppose constitutional monarchy is a compromise between monarchy and republic.
I need to stress what I think about royalism and monarchy. There is a kind of difference--monarchy is strictly the rule of one. That can apply to any leader, tbh (even the ones people would sack me for)--and then there's royalism, the household structure with kingship. Monarchy isn't necessarily royalism.
You sometimes get royalism w/o much monarchy and vice versa. Where the royal has a person of the monarch, but it's not really much of a monarchy (like the Doge of the Republic of Venice--an elected, not-so-powerful monarch, but in a political state that isn't necessarily a monarchy). I would describe those cases as having mere royalism and not much monarchy. Only the household structure of the royal estate is preserved, but what is left of the monarchy is little--kinda like the reverse they say with Roman Emperors, where they aren't really royal (Rome was anti-royal)--but they capture a kind of monarchy.