Yu might, but I don't think that I (or ;we') really do know. Some countries did much more, and some much less than us
By the media, and a fair proportion of the general population, but one would hope that all 'credible expert views' were 'respected and caredully considered by the decision-makers.
It sounds as if you are more clever than the rest of us, in that you know what advice was 'correct' and what wasn't. Most of us just see/saw differing expert opinions from which someone (government) had to decide which deserved the greatest ';weight';.
As above, I would hope that they were 'considered and debated' by the decision-makers. A #public debate' would have been impractical, since that could have gone on for 'years', whereas a decisio was needed in days.
As above, the media and a fair bit of the general population did, but one would hope that the decision-makers will not have dismissed/ridicukled any expert view/advice, but would have put it into the 'decision melting pot'
Maybe, IF anyone was 'incompetent', rather than just unable to be sure what was the best approach. However, the main individuals concerned are no longer in government, and the days of government itself are probably numbered - so who would you like to fire? About the only consistent thing is that everything done by government is done on behalf of, and with the implied 'blessing' of the monarch - should we perhaps posthumnously 'fire' the late Queen?!
You appear to have made up your mind about how government decisions were made, and what was 'correct' or 'incorrect (i.e. 'a pile of assumptions'), and are phrasing all your statements to fit with those beliefs. How is it that you know (rather than merely 'assume') more than the rest of us? As far as the rest of us is concerned, this is why we very much need an Inquiry - but about 'what', not 'who'.