It seems being the British PM is a short-lived occupation.
Patrick Watson, a CBC producer/director/CEO/etc., recently passed away. Circa 1990, he put together a documentary called "A Struggle for Democracy". He tried to define "democracy" but could not find that definition.
I sort of gave democracy my own definition: "When a leader of the governining party willingly steps aside after the people have spoken in an election."
In 2015, the somewhat xenophobic prime minister of Canada called an election. The polls were in his favor. But something happened. His party lost. He stepped aside. I just thought that was so amazing. Historically speaking, rulers do not step aside. The USA had their losing leaders step aside until 2020.
Your article raises some great points. It does appear that the antiquated UK system performs better than the modern US system. Different electoral structures do contribute to different outcomes.
But we also have to remember that UK system still contributed to bad decisions and controversial characters in high office. In my opinion, the UK system (which is very similar to Canada's) is not best form of governance humanity can ever invent.