I would lower corporate tax in Australia to 10%
And have a flat income tax of say $5k per person per year.
If you don’t pay you lose your citizenship
Discussion
Where do people go that lose their citizenship.
Nowhere. They can stay if they want. They just lose citizenship and the privileges of it until they pay
The number one privilege of citizenship is access to territory.
Not sure what others you had in mind.
But disenfranchisement has a bad historical record. Think black people in the USA back when or serfs in feudal societies.
Well they lose their passport so they lose access to the world.
That was bad because it was based on race or class
If you exclude people that don't have $5k then that's class immediately.
The rest will vote to raise the tax to $50k to exclude more people.
As for access to the world that's not on most people's mind.