Canadian banks are much tighter regulated.
Yes they are.
Plus, there are I believe 5000-6000 less regulated, compared to Canadian regulations, America Banks plus thousands of less regulated quasi-bank, financial institutions that are not classified as banks.
Whereas in Canada there a few dozen federally regulated banks plus a few dozen less regulated quasi-bank, financial institutions.
The banking and financial systems of both countries started, grew, were regulated throughout the decades and centuries on different footings, models and regulatory regimes. Individual American states were given much greater authority and regulation over their banking and financial systems whereas the Canadian system stressed federal authority and regulation. The proliferation of city, county, state and regional banks and quasi-bank, financial institutions in the states compared to the Canadian bank and quasi-bank financial institutions attests to the very different history, growth, models and regulatory regimes of both countries.
The above in addition to a regime of less regulation/more enterprise and risk taking has led to the American system being much more prone to risk taking and the consequence thereof than the Canadian model.