The result is substantially more democratic, as per the list above.
The result seems substantially more chaotic.
And then there is the fact that the entire legal frame work is based on The Crown. If the king or queen killed someone they would have to prosecute themselves. This is the exact opposite of democracy.
It's entirely mad to me that I can make a list of easily verifiable, massively important examples of democratic processes in this country in the last few years and someone would just come up with a hypothetical like "but what if King kills someone" like it's somehow not just equal but has more weight than the list. Mad
Anne Boleyn, Catherine Howard would like a word.
But processes that exist to preserve democracy that arent governed by that democracy are problematic. Saying the "king would never do..." when a king has makes the argument silly.
The UK is not alone in this - a great example is the filibuster in the us (a senate rule).
Queen Elizabeth used Queen's Consent many many times to prevent or modify laws she didn't like. An investigation by The Guardian revealed that more than 1,000 parliamentary bills were subjected to Queen's Consent or Prince's Consent during Queen Elizabeth II's reign.
The British government feels like a delicate standoff between Parliament and the crown.