Australian banks: Too big for their boots?

Australia's big four banks delivered a combined $31.5 billon in profit this financial year, an increase of 6.4 per cent on last year when inflation is running at 1.8%. The difference between RBA cash rate and home loan rate used to be less than 1.8% in the 1980s 1990s and 2000s, now the difference has grown to 3.75%.

Yet outlook can change very quickly for the big four banks in Australia considering we have the following risks:

• Housing slowdown or even collapse
• Increased political pressure if a Labour government were elected. The Coalition has lost 22 Newspoll opinion polls in a row and Labour is calling for a banking royal commission which would certainly shake up the status quo.
• Labour could consider creation of another state owned bank to force competition and return any profits to the government.  New Zealand already created KiwiBank, a state-owned bank run by the NZ Post Office. Australia could easily do the same.
• New competition from cashed up digital behemoth, examples are Amazon, Apple, Google and Facebook, they have a combined market cap of US$2.49 trillion. They could offer better digital experience, lower interest rates and they have millions to spend on lobby groups to overcome any obstacles. 
• Blockchain based digital currency allows secure store of and transfer of  value at a fraction of the cost, it has potential for massive disruption to banking. It allows for transactions to be transparent and visible to all concerned parties, offering anonymity when needed. Similarly, it reduces the risk of fraud, as records are unalterable after accounts have been settled.

Update 27/11/2017 - Royal commission into banking: The inquiry that could kill the Government:
http://www.abc.net.au/news/2017-11-27/how-bad-are-our-banks/9194984?smid=Page:%20ABC%20News-Facebook_Organic&WT.tsrc=Facebook_Organic&sf174349147=1
http://www.theage.com.au/comment/banking-inquiry-why-the-big-four-still-have-a-stranglehold-post-gfc-20171125-gzsygu.html

Bank inquiry almost certain after Nationals secure crucial second vote:
http://www.afr.com/news/bank-inquiry-almost-certain-after-nationals-secure-crucial-second-vote-20171126-gztb4h

Since the financial crisis, Australian banks have forked out more than $1 billion in fines and compensation from rorting their own clients:
https://www.documentcloud.org/documents/4310476-A-Summary-of-Bank-Transgressions-During-the-Past.html

Report; What is price stability? Market design in the Australian banking sector:
https://percapita.org.au/wp-content/uploads/2014/11/What-Price-Stabiliity.pdf

Update 6/7/2018 - The drop in NPS for the Big 4 since Royal commission - Reputation at lowest level recorded: