Self-isolation is a pragmatic solution. The problem is population density. It's apples and oranges for most Americans. They live in such a density as to make self-isolation very difficult. School closures lead to teenagers going to the mall instead and not stopping the spread of illness.

Because parents work, they bring home illness. It's that simple. There's little chance of self-isolation.

Now the cities with lower incidence rates and lower case-fatalities in the 1918 Pandemic, they closed businesses, school, public functions, funerals, etc. They did self-isolate successfully, but we're not there yet.