While not wishing a case on anyone, WA really doesn’t inspire confidence that when a case happens they are prepared to act. Instead everything has been put into hard borders, there’s no defence in depth or testing of procedures.
Other states have had to be more active in testing their procedures and you saw how quickly SA was overwhelmed, from a procedure point of view, with queues for testing and having to turn people away as an example.
The community is not prepared either, SA showing panic buying is still a thing in November 2020. The lack of social distancing creates a tinderbox if there is a hotel breach.
I note WA is very reluctant to increase hotel quarantine numbers either.