Here in Brazil, a Supreme Court minister has ruled on several occasions to block certain websites and services, the most recent being X/Twitter. Along with his decision to block these websites, he also imposed fines on those caught using VPNs to bypass ISP blocking. Although VPN traffic is encrypted and impossible for governments to monitor, somehow this worked because several people were fined. It is likely that Supreme Court agents monitored these networks in order to detect possible Brazilians using them during such blockages. An Australian should expect their government to proceed in a similar fashion.
(Just for clarification, I’m not going into the merits of this, just stating that this is technically possible and that there is a precedent in the government of a country, in aforementioned case, Brazil. Whether this is good or bad will depend on many factors)