Ach, I find these threads fascinating.
I have quite a bit of insight into Tory grassroots politics, and Sunak lost, fundamentally, because the grassroots thought he was too rich and they didn't want another public-school type in the top job because they are too divorced from the reality of the country. The grassroots are sick of Etonian types.
This does not mean, however, that they wanted Truss. A significant number of them I've spoken to actually hoped that Kemi or Wallace would make it.
This economic problem goes back to 1997 because Labour had made a manifesto commitment on a) schools and hospitals and b) to stick to Tory spending plans in the first term. They discovered, once they got into power, that there just wasn't the money to deliver a), and they were further hobbled by b), but this was tricky because they'd spent years developing the "evil Tories want you to live in slums" line. So that's why the expansion of PFI came about -- it was a way to deliver capital projects a) without contravening b).
Only in 2001, they were no longer committed to b), but had already discovered that the tax take didn't have the capacity to fund a) or, indeed, very much else. So Brown not only spent up to receipts, he even borrowed YOY during the "boom" between 2001 and 2007. Of course, when the "boom" collapsed (because it was entirely predicated on cheap credit), tax receipts collapsed by £200bn -- in essence, tax receipts shrank back to the level they had been in 2001 (this was entirely predictable). But the state was still committed to 2007-level spends.
Hence ... the need for austerity, which was, in short, an attempt to get receipts and expenditure more in balance, which was even more difficult because the public sector was hobbled by expensive PFI liabilities.
Then Boris the clown came along. And the pandemic happened. And Boris panicked because the narrative is "everyone is going to die." Cue: huge amounts of spend, like confetti chucked into the air.
We come to now: shit books, PFI liabilities like vampire squids stuck to our backs, everyone running around like headless chickens, unnerving price rises, housing costs sucking the blood out of the system, former QE that still hasn't been removed from the system, increasing energy prices ...
... and it comes down to this. It does not matter what political party you talk about, the issue is the very nature of the political narrative in Britain. It is far too adversarial. You cannot govern and run a country successfully (or, indeed, anything) with a blue team versus red team mentality. It's not a game of football.
Good governance requires people to engage with reality, and not let ideology, whether it be on the left or the right, get in the way.
The media is largely to blame for this climate, but activists do not help (and actually push away the people that we really need in politics). Neither do the attitudes of some MPs. To some extent, Corbyn recognised the problem and tried to do something a bit different at PMQs, but people just scoffed at him.
And to those arguing against FPTP, if Britain had PR, we would have had a decade of a parliament where UKIP would have been a powerful minority in the HoC. If we had AV, it would have benefitted UKIP, the Greens and the Lib Dems.
I'm not massively happy we have Truss. But I wouldn't be massively happy with Starmer either. Ain't nothing happening over the next ten years apart from dealing with this economic mess and attempting to keep the show on the road, regardless of who is PM -- it's just that if it was Labour in charge, the anti-Tories (apart from whoever is in the SWP at that point, and no one listens to them anyway) won't scrutinise government actions for any bungs to the super-rich.
TLDR: It's all a huge mess. Both parties are to blame. Liz Truss is a side matter. Hold onto your hats. Think frugal. Support the vulnerable in your communities. Insist on good governance and say no to willy waving and battle politics.