Until you use your credit card. Interchange fees in Canada are a full 1% higher than in the US, on average. You pay for this in higher prices on goods and services.

Or until you buy something in USD. Foreign exchange fees in Canada are a multiple of what they are south of the border, and Canadian banks ruthlessly protect this business by refusing to bank money service businesses that compete with them.

Canadian banks are the most profitable in the world, and they're really good at making customers think they're not paying that much for the pleasure of feeding the oligopoly.

Yes, that is probably true: I have kept a minimum balance ever since opening the bank account so I am not really familiar with how it all works. I have heard the horror stories though about how the bank will order the transactions to incur the maximum fees (at $20 or more per transaction) if you miscalculate the balance when the bank account is close to empty.