If the real number of cases is double that, then that would be a death rate of ... about 0.6%. And not everyone catches the disease in one pandemic wave, so the total population death rate in the US isn't going to reach that.
And the idea that the US is going to roll over and shrug when their hospital system falls apart is nonsensical. It is one of those sounds-scary-not-likely scenarios that doesn't play out at scale. The part people were initially worried about - ventilators, which can't be quickly scaled up in an emergency - turned out not to even be especially useful in managing COVID.
There are basic questions about whether the hospital system would have been overwhelmed in practice. People keep saying the response was bad, and yet there aren't any instances anywhere in the world I'm aware of where the hospital system really crumbled under pressure. There were lots of instances I heard of where where some people didn't get treated, and that is bad, but not so bad that death rates more than doubled to like ~1% in a local area. And even if the hospital system literally vanished, an order of magnitude worsening from 0.6% still wouldn't get death rates to 10% of the population.
It has been 2 years. We have the data now. 10% was never a possibility although that was less clear in the opening months. Even 1% appears not to have been reached in practice with the worst response policy response of any country in the world.