One person has a cough and the whole of the financial capital of the perfect utopia that is New Zealand is shut down. https://www.nzherald.co.nz/nz/covid-19-coronavirus-auckland-into-level-3-lockdown-nz-to-alert-level-2/VICFSFKSMGMQRU2WKBTIT7BPAY/
This response doesn't make sense even on the 'logic' of eradication. The whole point of eradication - of exceptionally dangerous diseases like smallpox and Ebola NOT C19, but we'll put that to one side - is that you can contract trace the v v limited number of infected people.
Not that you must shut down an entire city because of one incident.
And note that WHO advised in November 2019 that contact tracing - attempted against that advice around the world with exceptionally disproportionate effects - is pointless unless the disease is at the v beginning and there are v few cases.