Canada largely escaped the subprime crisis and not because of the Volker rule or because of Glass-Steagall - which Canada has no equivalent of. It’s all a question how much leverage you allow banks to have. You can’t “safe” them by merely excluding certain investment classes. That backfires because it makes it harder to diversify risk. We saw this with the government-made S&L crisis of the 80’s. The feds thought they were making S&L’s safer by limiting their choice of investments but when the oil patch went belly up and oil patch real estate with it the reverse turned out to be the case.
AFAIK, max leverage is dictated by Central Banks. Fiat money and fractional reserve banking system facilitate growth of economy. However, these systems are inflationary and can be easily misused/ abused by incompetent government. Some1 need to improve the systems. For ordinary folks like us, the survival tip is to adapt 
Fractional banking is only for the benefits of the bankers. Inflation is a clever way to steal money from savers and hand it over to the borrower.
Fractional Banking/Central Banking do not promote growth. I do not know why you said that. Growth and Contraction are phases of natural economic cycles. The economy and civilization has been growing for thousands of years without central banks, fiat money, and fractional banking. The only people who grew with central banks, fiat money, and fractional banking are the bankers and politicians.