There is this notion that South Korea tested aggressively, and early, which may be true, but they did not test even a large percentage of their population early. There is more to their success than just early testing.
If they had tested only a quarter of a percent of the population by mid-March, that is not to me a sign of wide spread testing. I'm sure they tested folks who showed symptoms and then did contact tracing to the extent possible, not just rep sample testing.
I am beginning to think we will have to have a treatment with an antiviral that works well, not a vaccine, and not herd immunity.