@Inky online banks have their place, so too do credit unions. It also depends on what credit union you're comparing with. Some CUs provide free accounts like the online banks but still have the option to get either free or PAYG branch access for the times where branches can resolve things faster.

If all you want is a no frills banking experience, online banks are great but CUs still fill a role that can't be found with the Big Banks either. Really depends on what your needs are really.

@MacroCyclo

Regarding Brim & KOHO:

Well real question is what BMO card you have and what you wanted out of it. If you are currently holding say the BMO Cashback World Elite MasterCard, then ya, I can see why those 2 choices can't replace this card but if you compare it with say the Scotiabank Momentum Visa Infinite, CIBC Dividend Visa Infinite or even the MBNA Rewards World Elite MasterCard, then they can compete.

Really depends on what you're looking for in a card...