ACT has had basically the most libertarian version of Australian covid policy consistently through most of the pandemic. Very little police enforcement on the lockdown and restrictions, no vaccine passports or mandates, and I'm pretty sure was the only state or territory which never prevented any residents from returning home at any point during the whole border era.

Something like 99% of Canberra's adult population got the first two doses of the vaccine. There was almost no vaccine hesitancy here. So creating a "vaccinated economy" (as it was called in Victoria)... the benefits would not been worth it.

And Canberrans are generally very educated and compliant people (compared with Australia as a whole) plus it's more homogeneous than Sydney and Melbourne, plus it has a higher percentage of people who can work from home if necessary, so they probably didn't consider it a good use of resources to police it. Also, considering that we were moving away from zero covid anyway (going back to Aug/Sep 2021) and the ACT was surrounded by NSW, which had covid everywhere.