Australian banks are massively profitable. They also have the benefit of an incredibly generous safety net from the federal government.

They could easily be obliged to provide services for regional Australia, much the same way the telcos are.

https://www.abc.net.au/news/2023-10-06/regional-bank-branches-at-risk-of-closing-population-analysis/102937120 

 It would go a long way to fix the abuses by billionaires if using stock as collateral was treated as a capital gains event.

When stock gains are just on paper, they shouldn’t be taxed. But turn them into money - by selling, or using them as collateral - and they absolutely should be. https://www.reuters.com/business/media-telecom/elon-musk-borrowed-1-bln-spacex-same-month-twitter-buyout-wsj-2023-09-06/