If this is the falsehood we need to perpetuate in order to let guilty politicians save face and restore a semblance of sanity to our society, then so be it, but let's be unambiguously clear, this statement is incorrect.
The correct statement is: researchers knew, leaders ignored them, and media distorted them.
The WHO China joint mission released both CFR data (3.8%) [1] and IFR estimates (0.3%-1%) [2] in February, based on ~44,000 confirmed cases. They were both broken down by age and very similar to later studies based on other cases. There were no surprises after February, unless you were reading news headlines instead of actual research.
CFR as of February 11 [1]:
CFR Age
0.2% 10-19
0.2% 20-29
0.2% 30-39
0.4% 40-49
1.3% 50-59
3.6% 60-69
8.0% 70-79
14.8% 80+
Very similar age curve to the IFR estimates you posted.It was already very clear in February that this disease rarely killed anyone under 60, or even 70. Leaders just didn't listen.
To use the USA because I know it best, the first big cluster of fatalities was at a nursing home in Kirkland, WA which wasn't up to code.
So leaders had hard data based on tens of thousands of cases showing that this disease was dangerous to the elderly, and not so dangerous to everyone else. And then the first outbreak kills a bunch of elderly people. Amazingly, they responded to this by locking down the general population, and failing to take targeted measures which would protect the elderly (not sure right now but at one point 50%+ of US Covid deaths were in nursing homes).
It's the biggest failure of leadership in our lifetimes.
[1] https://www.who.int/docs/default-source/coronaviruse/who-chi... (page 12)
[2] https://www.who.int/docs/default-source/coronaviruse/situati... (page 2)
[3] https://www.weforum.org/agenda/2020/03/coronavirus-covid19-c...