What kind of moron would be jealous of someone else having a monarch? Laughable.
Nobody laments the loss of tradition more than Russians do.
Russia: Monarchist Nostalgia Remains Powerful
https://www.rferl.org/a/1071729.html
(Article was written in 2006 though, now Soviet nostalgia is more en vogue.)
Practically speaking. With regard to UK, consider this: Forbes reports the British monarchy “contributes nearly £1.8 billion to the UK economy” annually, including £550 million in tourism.