You're right. I chose the optimistic end of fatality estimates because that's the conservative choice (for making the point I was making) but given that infrastructure will collapse in this scenario the true fatality rate is almost certain to be a lot higher.

I would wager that a 0.5% mortality rate is closer to the “real” rate than the 5% figure.

Look at South Korea. Do you see a 5% CFR there? Of course not.

I don't think there's enough data to say for sure on this in the sense that outside of S Korea, very few asymptomatic people have been tested.

Not according to S Korea

South Korea's infections have all overwhelmingly come from the same religious group, which tilts heavily towards the 25-35 year old demographic. People in that age group have a very low chance of dying from the disease.

South Korea has kept their infection rate low enough that it doesn't overwhelm their hospitals. The fatality rate is more like 5% if you can't get treated because the hospital is full.