I have been trying to understand what the "boys club" did wrong? By my reckoning, Melbourne is the obvious location for these games. Would there be suitable venues available anywhere else?
Yeah, the best location was always going to be whichever government was willing to pay the most and that has clearly been Victoria. With the couple of years they've had event-wise it's easy to see why they were the highest bidder.
In the future Suncorp offers the same or similar availability and would almost certainly offer a boost on crowd numbers, assuming the QLD government maintains their general willingness to bid for big events. I imagine they decided to cool it this year after a bumper couple of years over covid though. Perth could be an option but time zones would mean the games have to be played earlier in the day which would potentially hurt crowd numbers and restrict the number of rounds in the season when the weather would be cool enough. Sydney is probably only going to be an option before the NRL season starts but the NSW government might just go hard for it to help justify the new stadium. I doubt Canberra will be in the conversation until they get a new or upgraded stadium.
There'd be plenty of availability and hopefully solid crowds in New Zealand, but unless the government is willing to pay for it I don't see it being hosted anywhere in New Zealand anytime soon. Time zones might also complicate things for NZ, as Australian broadcasters will still want Friday/Saturday primetime games, which might be too late for crowds (and local government stadium noise curfews).
If there's investment in facilities Fiji could be a smoky in ~5 years, but that would likely require Australian and/or New Zealand government funding to stack up. That's definitely not out of the realm of possibility with the way things are going in the pacific though. Wouldn't be amazed to see a neutral venue like Tokyo, Singapore or Hong Kong bidding for it in time, but crowd numbers would probably have to lift across super rugby first to justify it for them.