Well, it's China.

> The UK appears to have decided allowing 500,000 of us to die was a bad idea and we're now on "lockdown".

500,000 people dying wasn't going to happen. Korea's death rate is closer to 0.4%, almost entirely the older folks who were to be quarantined at home during this process anyways. Korea's death rate for under-40's is 0-0.1%, so at worst, ignoring that vulnerable folks in those demographics would also be quarantined, the death toll would less than 50K -- probably much, much less, and not drastically out of line with a bad flu year.

> I'm not sure we can tell what the rates are, what's the testing false positive rate? UK gave up testing a while back (except emergency hospital admissions).

Supportive treatment is the only thing you can do anyways. Beyond that PCR tests will only tell you if you currently actively have the disease not if you had it before and recovered. We need antibody tests for that.