What exactly would the chain-yanking look like? "Make your online banking suck!" "Charge random fees in an opaque manner!" "Make your customer service worse!" ?

What exactly would the chain-yanking look like? "Make your online banking suck!" "Charge random fees in an opaque manner!" "Make your customer service worse!" ? And if they do have their chains yanked, they can switch their provider. It's not like banks have "coverage" to lock you in, like mobile networks.