If any paleos ever find themselves nostalgic for monarchy, all you have to do is read up on these characters. There is more drama and intrigue with these folks than there is on Days of Our Lives. Check out the wiki on Richard III. It’ll make your head spin.
Correlation may not always be causation, but the bottom line is that there is a precise moment when Western culture went into the toilet, and that is at the end of WWI, when the traditional aristocracy lost the last of its political power over most of Europe. The NSDAP tried to offset this, but it didn’t have enough time.
The bottom line: for whatever reason (though the reasons are not hard to determine), only the aristocrats were able to control the culturally corrosive power of you-know-who. Once the aristocrats fell, there was nothing to stop the ascent of the hostile elite.