That is one argument. Here is a different one:
I see a lot of this going on: mentioning 13, possibly 14 years in power, but can I remind people the first 5 years were in a coalition with the hopeless Lib-Dems.
Furthermore, Boris Johnson got elected with an 80-seat majority in December 2019 - he was just getting going in early-2020 and then Covid-19 happened. We could argue for hours if Johnson and the tories dealt with that correctly or not, but the fact is, it wasn't his fault. Then, just as Covid-19 was pretty much sorted out (early-2022) Vladimir Putin invades Ukraine. We could argue for hours if Johnson and the tories dealt with that correctly or not, but the fact is, again, it wasn't his fault.
So now we come to the middle bit: David Cameron, Brexit & Theresa May. We don't need to argue for hours on that one, she should never have been Prime Minister.... why appoint a 'Remain' supporter into the top job, to deal with that, once the referendum result was for Brexit? "Brexit means Brexit" what a load of rubbish - if everyone in the House of Commons and the House of Lords (and the civil service) had accepted the democratic decision of the British people and acted to sort it with as much speed as possible, lead by someone totally committed to it, even the middle part of this Tory timeline might have been different.
This Tory government are in their death throes, I accept that, but how much is it their own fault and how much is it to do with pro-remainer civil servants, old-farts in the House of Lords, plus international events over which they had absolutely no control at all?
P.S. why did you say con-men as the worst of the lot was a woman: Theresa May. If you can't easily beat Jeremy Corbyn in a General Election, you should resign from politics.