My (very rough and possibly incorrect) understanding was that there was a lot of government subsidies of things and lots of government jobs that somewhat existed just to employ people.
This resulted in huge government expenditure as rich/middle class people took advantage. (I heard something about heated swimming pools as electricity was so subsidized. Not checked that though) This meant that the government was always teetering on bankruptcy (again) and the economy never really grew.
My understanding was basically that the country was pretending to be much richer than it was. This is more about resetting to what it can actually afford - hopefully setting itself up for future growth.
If the government went bust, most of this would have happened to an extent anyway. I’m not sure what other options there where, I think the other option at the election was to spend their way out, but they had no money and that would have pushed inflation even further.
Almost anything might have been better than nothing. They voted for it and he still seems to have high approval ratings 🤷♂️