There is of course no shame in being a subject rather than a...

There is of course no shame in being a subject rather than a citizen. Some nations prefer to be subjects.
England, Wales and at least 54% of Scots certainly do.
To me it signifies a fundamental lack of confidence in a country's own ability to rule itself and an ultimate deference to inherited privilege and wealth. A kind of internal colonisation of the mind. A prostration in front of ones perceived "betters".
Like the slaves who refused to leave their masters plantations when offered freedom in the USA 1865.
That's their decision.
It wouldn't matter if the UK monarchs were an interesting but uninfluential footnote in Hello magazine as they are in Denmark and Sweden and we had an equitable society. And if the Royals actually worked for a living like everyone else. But the UK Royal Family does interfere and influence politics , contrary to the official line, and in the UK we have the most unequal and poverty stricken society in the Western world with the exception of the USA- who have their own Hollywood style of President King.