The “big five” banks in the states actually represent less than half the American population, whereas the major banks in Canada cover about 85% of us. (Note these numbers are from before the pandemic - I’m no longer involved in the banking industry.)
The US system is still incredibly fragmented, though a lot of consolidation is happening (yay oligopolies). Canada, on the other hand, has had stricter regulations for longer, which meant that even the 15% of Canadians with small banks and credit unions were included in the changes to the industry as they happened.
If pp cares so much, he can get the security clearance and look at the list himself.