Were there other safer alternatives that they could have gone with? What could be the reasons for choosing this combination over those safer alternatives?
(There was some stated nonsense about reducing tax bills increasing growth, but trickle-down economics has never been proven to work and they weren't interested in that)
My guess is scorched earth. BoJo is such a disaster that his own party had to remove him - and even that turned out to be a struggle (getting rid of leaders with challenged hair seems to have been a struggle lately on both sides of the pond). He became that unpopular.
The crew that have replaced him have no chance of winning the next General Election; Truss has even said that she knows she's unpopular, and doesn't care. So by running up the debts, they set a minefield for the next Labour government, which will have no alternative but more austerity. So I guess the Tories are planning to win an election in 7 years time.
I've heard rumours about Kwarteng being involved with Hedge Funds that have now made a fortune by shorting the pound and to be honest, that makes more sense than any other explanation.
No government with morals could do the sort of borrowing + tax cuts that the Tories are doing. That means down the line a moral government has to be austere and have higher taxes, and so the people will just vote in the Tories again. Only complete societal collapse will stop that cycle ...
Ergo having a climate change denier in charge of business and energy is a good thing! /s
Corruption.