I don't live in either city, I have family who live in both Melbourne and Sydney so I travel to each city relatively frequently at least a couple of times a year. My experience was Melbourne had their system years before Sydney had Opal cards.
I can distinctly remember first time using tap on/off card to get around Melbourne and thinking how much more convenient it was then needing to use Paper ticket machines Sydney had at the time.
Wikipedia lists 2008 adoption for Melb vs 2012 for Syd that seems to align with my memory. So might have just been curse of them being an early adopter.
Other countries had it before Melbourne and rolled it out smoothly. Hong Kong launched theirs in 1997. 11 years prior. Melbourne could have easily bought it off the shelf. Melbourne was not early by any measure
What I'm trying to say is that it was mismanagement, which was well known at the time. Hong Kong also has Metro, trains (at the time), buses, trams, ferries. All from different companies. In Melbourne they are actually mostly under the same government agency.
The Hong Kong system's backend, and large parts of the frontend, was also written by an Australian company, ERG at the time, now VIX. So there was plenty of local skills that _could_ have been used.
Brisbane had trials for a Cubic system in 2006 with a full rollout by 2008. It went, broadly speaking, OK. The machines at stations were a near unusable mess and the locations you could buy the cards from were ridiculously limited.
I can distinctly remember first time using tap on/off card to get around Melbourne and thinking how much more convenient it was then needing to use Paper ticket machines Sydney had at the time.
Wikipedia lists 2008 adoption for Melb vs 2012 for Syd that seems to align with my memory. So might have just been curse of them being an early adopter.