I suspect the high tax no longer has much of a harm reduction/uptake suppression utility, and that the Aus government secretly knows this, but they are hopelessly addicted to the revenue so will enact overbearing new laws to protect the income stream.
The reasonble approach is to wean nicotine users off black market product by removing the price disparities. The only way to do that is by accepting a much lower tax intake than the current arbitrary, punitive one (perhaps VAT * 1.5 or 2?)
I remember the Australian government crowing about their world-first plain packaging initiative many years ago. Talk about fighting the last war lol