The Australian ecosystem specifically makes all of those sectors, and future sectors, equally responsible for taking their share. If it's banks alone, you end up trying to stop the fire when it's already raging. There are things that banks can, should and must do to secure their platforms.
Particularly for the telcos and platforms, when they take action earlier, it's possible to intervene in scams earlier. The vital link here is sharing information across the sectors. When a bank becomes aware of a scam victim, if we can share that information with a telco or platform.... It is too late to help the first victim—that is true, and it's devastating—but at least the information can then be shared back to clean up the pipeline of future victims.
Over time, it makes it a more expensive proposition for the scammers to target Australia, as opposed to another country, so they might put their efforts elsewhere.