tl;dr is: Shitstorm on the horizon, Various MPs put name forward, Votes happen to pick winrar, grenade wins

Ironically the voting happens in ways the Tories never want to implement, where the lowest result gets eliminated each round. End 2 then get put forward to the paying members of the Conservative Party who pick who gets it, this number essentially means an Oligarchy. UK doesn't vote for PMs the way the US votes for Presidents. US might vote AGAINST/FOR Clinton/Trump for example however the UK votes along party lines with the leader of a party most often being the PM if that party wins a majority or can arrange some deal like happened with the ConDem coalition that resulted in the LibDems killing any and all future attempts of eligibility for the next few decades.

This time the final round was between Truss and Sunak however Truss is called "the human hand grenade" and Sunak was the chancellor during Lockdowns which included such massive fuck ups as "Eat out to help out" that inevitably caused even more spreading cases. He is quite literally the richest MP in government right now being a multi-millionaire himself and having married into a multi-billionaire family and is so detached from common reality he's had such spectacular PR failures that include:

Failing to put petrol in a car, a car later revealed to not be his

Failing to use a contactless debit/credit card reader

Both of which are daily activities for the general population meaning he's never going to be seen as someone who represents anything "the common man" might do. Unfortunately the other option was Truss...