TBH I'm sort of baffled by this stance given the events around Queen Elizabeth II's passing.
To be clear, I'm not a monarchist, and I share the opinion that their continuation in modern society is, well, weird, to say the least. A modern constitutional monarch holds no real power, and often times holds less power than normal people (e.g. not being able to express any political opinion). For example, I wouldn't wish being a member of the UK Royal Family on my worst enemy - yes, you are rich and nominally "famous", but you essentially have no freedom: your job in life is pre-ordained, and your life is basically constantly under the microscope of an adversarial press.
But, while I may not fully understand it, it's clear to me that a monarch can serve a real purpose in modern societies. Many, many millions of people felt an affinity and dare I say a love for QEII, and I think these traditions serve a unifying force in the UK, or at least in England. The UK monarch and royal family are essentially the ultimate "branding" exercise. Plus, since the UK has basically separated any real power from the monarch, it means that the monarchy's sole purpose is to serve as a "neutral" symbol of the state, something that pure democracies often lack.
To give a good analogy: I don't really understand rooting for professional sports teams either (George Carlin has a great bit about this "The players change, the coaches change - you're basically rooting for laundry"), but clearly tons of people have a deep, strong emotional bond to their "favorite team". It's also clear to me that, even if I don't understand it that well, many people can feel the same way about their monarch, and that can serve an important purpose.