Is monarchy always the best form of government? A Vox article says that it is. We should be very sceptical of anyone claiming an absolute rule on form of government. Every country - including New Zealand - is different.
No, becoming a republic doesn't "end" of the Treaty
Local elections: a modest proposal
An "expression of regret" from the British government
UK: 62% of Labour members support a republic
Brexit: Monarch is not a constitutional check
For years, supporters of the monarchy have claimed that the Queen represents a significant constitutional check on our politicians and is politically neutral. The British Prime Minister Boris Johnson's request to the Queen to prorogue (essentially suspend) parliament for a period, whatever your thoughts are on Brexit, highlighted this contradictory claim. If there's anyone who should not be surprised at the anger being directed at the Queen for her decision to follow hundreds of years of constitutional conventions, it should be those supporters.