Thinking about my opinion of Cameron, perhaps Prof D and I are not that far apart but are hung up on the effect of words.
Incompetence to me seems to reflect a pattern of behaviour. Johnson to me is the most consistently incompetent PM of my time. His reverse Midas touch being 100% effective but he did win an election with an unfortunately fecund majority.
I am not sure of the right word for Truss, as a distilled intense month of crap, perhaps to paraphrase Percy from the 2nd series of Blackadder, she 'had discovered purest shite'.
Cameron, on the other hsnd, had won 2 elections, an unusual enough achievement, his second victory an indication of some success in his first term, given a majority. He managed being PM through a period of coalition, and his first term was not the serial farce of Johnson.
He had used referendums to first pacify his coalition partners, and then 'rebellious Scots to crush.' And therein lay the decision which I think there might be more agreement on was the most costly to the UK of PMs of my lifetime.
The third referendum happened, not I would suggest, because of incompetence, but rather a hubris similar to that which befell Thatcher and Blair as they won elections. The chance to forever heal the generations long divide in the Tory Party. The chance to remove the wailing chancre that was Farage, and by using his favourite sword of democracy the referendum.
And he would choose the battlefield of the bumpier electoral roll, not out of complacency brought on by his upbringing, but that very hubris that his success in power had brought about. He would do it for what were to him the purest of reasons as it would silence any doubters, if they seemed to choose the field, not him. The dragon would be slain, and none could cavil that the fight was unfair.
Even as the skirmishes started, he didn't want any accusation that it wasn't a fair fight so the Remain campaign happened with him cheerleading more than vanquishing. As the battle heightened, he saw the need to get more involved but found it had shifted away, yet still the entrails examined by the haruspices of William Hill and Bet Fair seemed to side with him.
But, as so often, the gods used the fool to betray him. His thrice democratic campaign fell from the first in the vadts of Sunderland in a land now sundered, where Nigel blew(his own trumpet) and UKIP chundered. Despite his once doughty foes, the Scots sacrificing themselves in numbers that seemed already mythical, the heat of the sun god melted the wings of the man who would be the son king of both the Blessed Margaret and the Titan Tony.
He fell, he fell through air and time, holding once onto a passing green sill but somehow believing, knowing that like another lost general he would return, like another sacrificed son king, his demise was not permanent.