The IMF said today:
[Banking] Supervisors should focus more on the business models of banks to ensure sustainable profitability. We estimate that almost one-third of systemically important banks, with $17 trillion in assets, will struggle to achieve the profitability that’s needed to ensure their resilience to shocks.
To put it another way, these banks do not have a sustainable business model, have vulnerable balance sheets, and as a result could be the mechanism to transmit risk through the financial system.
And that's precisely why another global financial crisis is likely.
What is more, a decade after the financial crisis was created by the world's major banks they're still the source of the biggest risk we face. It's not encouraging is it?