I agree Australia doesn't get to dictate what people do over the internet from remotely.

Neither does the EU.

Neither does China.

If you violate China's laws with your website, they block you. They don't need you to change your website. It's very simple.

If you violate GDPR, the EU is welcome to block you.

If you violate weird Australian laws, Australia is welcome to block you.

No different. Just that (hee hee) we know the EU and Australia won't dare set up national firewalls. But from the perspective of the website owner, they're welcome to set up a firewall if they don't like the website. But the website isn't going anywhere.