For an Australia, you pay income tax if you're a resident for taxation purposes. For an Australian Citizen to answer that they're not a resident for taxation purposes is complicated and depends in part on the type of Visa you have.

Last I looked, for me, as an Australian citizen, to not have to pay tax would mean getting a permanent Visa in another country and being resident in that country. They specifically excluded time-limited visas, even if you can get them renewed automatically.

It means travelling around the world, even for years at a time, I still need to account for my income and lodge tax returns in Australia. The one upside is getting credit for income taxes paid in another country.

I believe a similar situation also applies to Canadian citizens, as a few former Canadian colleagues in Australia had to go through a whole process of getting their Australian taxation recognised in Canada.