> Italian lockdowns didn't stop COVID - human immune systems did.
That might be true for Bergamo, but certainly not for the rest of Italy, especially outside of Lombardy which had much lower infection numbers and death numbers.
Having as many dead as in Bergamo everywhere (0.58% of the whole population according to a short google search) would be unacceptable.
Blood donors in London ~17%, rest of UK ~10% in July; 45k deaths for <20% antibodies (which may or may not mean immune)... seems to me that without a lock down the UK at least would have been looking at 200k deaths before getting close to herd immunity. I'm not ok with that myself, but of course opinions may vary.
You cannot just extrapolate like this. Maybe those numbers are true. Or maybe virus have already killed the most susceptible, and more infections would not translate to more deaths. Maybe… All is just a speculation.
At a very basic level, of stats and epidemiology of course I agree and you are quite correct.
However, that is the stuff of the future and the ivory tower. In the course and flow of this public health crisis it is necessary for reasonable speculation and extrapolation to be used to drive our responses.
There is no evidence that I have heard that the most susceptible have been culled from the population yet, and there is no logical reason to believe that this has happened. In fact the contrary seems to be true when the pattern of the outbreak is observed in the USA. Potentially there remain a huge well of victims left in the population.
To claim that this abet contingent knowledge is illegitimate in the face of the human catastrophe that could result from rejecting it strikes me as an rejection of all of the principles of the enlightenment. Our rationality is our sword and shield for fighting the shadows on the wall of the cave. I for one will not be putting these tools down. It is wrong to cower in the dark when our brains can light a light and let us see a path to safety.
If all of the world reached Bergamo stage, there would be no way to test 57% of the world population.
That doesn't mean there are 46 * 18 million cases world wide -- the deaths would be catastrophic world-wide, just like they were in Bergamo.