// Whilst I have only "speed read" it, the report from the first of your links (UK Pandemic Preparedness) was only published some nine months after the pandemic began in the UK so I cannot see how it helps to examine the decision making that went on in March 2020.//
The part which is most relevant, to the point I was making at least, is the part where it talks about how the initial plans, the ones that you insist would have worked, were developed to respond to a flu-like virus. But Covid is not flu (despite many people insisted at the time), either in a literal sense in the manner in which it spread. As a result, it seems pretty unambiguous that (a) the plan failed, (b) because it was targeted at the wrong thing, and (c) the responsible people didn't adapt to this in time (this last is discussed in the links I reproduced above).
In response to a disease, a blanket Lockdown, particularly of the length we saw at the start of 2020, is an admission of failure. It means that other measures either weren't implemented properly or have failed despite best efforts and intentions. In that sense, I think our conclusions are broadly the same: lockdowns cannot be allowed to happen again, and future pandemic responses must be able to adapt more rapidly to the novel diseases that await, be that administratively or otherwise.
Where they differ seems to be the extent to which that was already true this time. It certainly *could* have been avoided: the most relevant lesson is probably from countries like South Korea, or Taiwan, and hopefully their systems will be studied more closely in the UK and other Western countries, but in South Korea's case at least that system had been in place in response to SARS and MERS outbreaks from 2003/2014, so there was evidently time for the UK to pick up on this. But it seems perverse in the extreme to argue that the approach in early March was working, and that in that scenario lockdown was already unnecessary. If anything, the problem was that the reaction was too slow. Not necessarily in terms of going into lockdown already in February, or earlier in March, but certainly in terms of being too keen to avoid "panic" that the response wasn't escalated through more intermediate stages more rapidly. Some, or most, of this is hindsight, though, and I still maintain that the Government's response after that missed opportunity was, broadly, the correct one. It would, in particular, be a shame for one of the few things I give Johnson credit for -- that is, his leadership through that first lockdown (the other one being his response to the War in Ukraine, which was world-leading) -- to be taken away and dismissed as, after all, a panicky reaction that will become a stain on his legacy.