I feel like this is an extremely unpopular opinion but I really don't think republicanism was a step forward for humanity.
Monarchy is the most intuitive form of government. People tend to take care of what they own, and politicians have no incentive to leave anything better for the next generation because they really have no stake in their country. Their legacy dies with them.
A monarchy with constitutional (and familial) checks and balances is vastly preferable to a republic where the foreign interests run free and loot the taxpayers. It's pure and much simpler. No Congress, no Supreme Court, no ridiculous sham elections. Everyone knows who's in charge and what the rules are.
The monarchy isn’t the way to go. Even if you did have a good and just King, it would only be a matter of time before you got one that was neither. At that point you would have no rights or recourse.
For what it’s worth, the US is an occupied state that is operating as a capitalist republic in name only. It has been subverted and has devolved into a corrupt Marxist autocracy. If it can be recaptured and the rule of law put back into place it will probably be the best form of government on the planet.