But it's just curve-fitting. And it depends on certain things, like people being smart. You get your parameters from what you observe.
If you have a better way to do it please share.
We only have the same curves if we put in the same restrictions as Wuhan, or get R down as much. Yet we still have megachurches holding services.
And politicians are using these as worst-case scenarios already, which will make them complacent about the urgent need for more ventilators, masks and PPE supplies.
But if we behave and practice social distancing and don't do stupid things, this is the estimate we have today (or a couple of days ago) of the timeline.
If I were a leader of the United States, I would challenge the population to beat these numbers.
All that said, the math is brutal and you're right about things not being immediately apparent in the statistics. There's a delay for symptoms, and then another for deaths.
Unless another country epicly fubars their response, the USA should maintain its #1 spot. All the more so if states don't encourage social distancing for another week.
More interesting to me is that we have a measure by which we can evaluate our leader's response. Deaths well north of 200K means he severely screwed up.
Of course we'll never convince his base of that should it come to pass.
And to be fair, if he keeps the number of deaths in the 100K range then he will have done a good job from the point at which he started taking action.
Everything in excess of that is a shocking mix of incompetence, hubris and malice - including refusing help to states whose governors aren't sufficiently deferential.