In primitive societies, sick people go to a witch doctor who jumps up and down. Then when the person recovers (as usually happens) the witch doctor takes credit and so the respect and admiration for witch doctors is sustained among the moronic population.
Essentially the same process is now happening with the coronavirus at a national level. The national witch doctors advise the leaders to impose senseless restrictions on the population. Then when the coronavirus naturally passes, the witch doctors give credit to the senseless restrictions.
The one exception to this is China. I suspect that the original coronavirus was virulent and mutated fairly rapidly. The Chinese response was to focus quarantine on those with symptoms. This meant that those with the coronavirus but without symptoms were allowed to spread the less virulent variations of the coronavirus. By doing this, China bred the coronavirus to be about as virulent as the flu. So China effectively solved the problem of the virus, but not the problem of the collective insanity of modern culture.
Most numbers thrown around are meaningless because there is no accounting of people who had the coronavirus but had no symptoms. The only country that I know of that has real numbers is Iceland which reports a 0.3% death rate which is in the range of the flu. So the coronavirus should basically be thought of as a bad flu. Like any new virus, it starts with exponential growth in a new population but then levels off as herd immunity is reached. Extrapolating from the numbers during the initial exponential phase makes no sense.
I view the coronavirus as a gift from God, essentially God giving depraved modern culture the rope to hang itself. The collective insanity of modern culture should finally cause the long overdue financial collapse that modern culture deserves. And that is a very good thing because it will reduce the attractiveness of modern culture and allow alternatives to grow.
Summarizing, R0=3 implies a needed 66% immunity. With a mortality rate of 0.3% we have 0.3% of 66% of 300M Americans means 600K dead.
The problem here is that R0 is a fundamentally unsound concept. Consider a country where one small region has a very high R0 (for whatever reason) while the rest of the country has a low R0. So initially most cases will be in the small region and the reported R0 will overly reflect that region. As that region gets herd immunity, the R0 will drop to reflect the rest of the country. So one would expect R0 to drop over time, not only because of acquired immunity but also because variation in R0 across population groups will cause a skew from high to low over time.