There’s an article about a book in today’s Times which details the mistakes the government has made throughout the pandemic and how they ignored the advice given them by SAGE. I can’t do a link I’m afraid. I’ll find out the name if the book. If you read it it will answer your question.
I don't know if it's the same book, but I bought one a few months ago. It's called 'Failures of the State' and is by two Sunday Times journalists from their Insight team.
Also, I think there's one recently published called 'Spiked' by, I think, a former member of the No 10 team.
There have been a number of analyses of the conduct of the pandemic published over this year.
Government supporters might object that they are 'political' and 'biased', but all they do is pull together much of the information that has been available since the start, plus some interviews with leading actors, such as medical staff and civil servants.