Nobody with any sense plans their life around their pre-tax income figure and If they did they’d run in to the same issues whether they’re in Sydney, Perth or Darwin. Also the gummint aren’t taking 47% of their income.
That’s also a pretty huge generalisation, not everyone wants to live in their parent’s pockets their whole life. Clubs like Warriors, Cowboys and Storm manage it let alone all the players who’ve done stints on the other side of the Earth in England/France.
Funny you mention those clubs, How many recruits are they signing on single year deals from say Brisbane and Sydney?
No one is saying in their parents pockets but wives in particular need family given the life of an NRL player.
As for the player themselves, Of course they want to leave the nest but they aren't going to leave halfway through courses or whatever they are doing off field.
Your England example as you used also very few young ones go over. Certainly not without a multi year deal, Same applies for NZ, Cairns, Perth and anywhere wanting a team. Players and coaches are the biggest issue with expanison.
As for the tax rate, isn't 47% what Kiwi, poms and anyone not an Australian citizen pays?